Add prefers-color-scheme support (#601)

* Add prefers-color-scheme support

This should fix <https://github.com/omarroth/invidious/issues/559>.
The cookie storage format has been changed from boolean
("true"/"false") to tri-state ("dark"/"light"/""), so that users
without a cookie set will get dark mode if they have enabled the dark
theme in their operating system. The code for handling the cookie
state, along with the user's operating system theme, has been factored
out into a new function `update_mode`, which is called both at window
load and at the "storage" event listener, because the "storage" event
listener is only trigerred when a change is made to the localStorage
from another tab/window (for more info - see
<https://stackoverflow.com/a/4679754>).

locales/ar.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "عرض مقاطع الفيديو ذات الصلة؟",
     "Show annotations by default: ": "عرض الملاحظات فى الفيديو تلقائيا ؟",
     "Visual preferences": "التفضيلات المرئية",
+    "Player style: ": "",
     "Dark mode: ": "الوضع الليلى: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "الوضع الخفيف: ",
     "Subscription preferences": "تفضيلات الإشتراك",
     "Show annotations by default for subscribed channels: ": "عرض الملاحظات فى الفيديوهات تلقائيا فى القنوات المشترك بها فقط ؟",

locales/de.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "Ähnliche Videos anzeigen? ",
     "Show annotations by default: ": "Standardmäßig Anmerkungen anzeigen? ",
     "Visual preferences": "Anzeigeeinstellungen",
+    "Player style: ": "",
     "Dark mode: ": "Nachtmodus: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Schlanker Modus: ",
     "Subscription preferences": "Abonnementeinstellungen",
     "Show annotations by default for subscribed channels: ": "Anmerkungen für abonnierte Kanäle standardmäßig anzeigen? ",

locales/el.json

@@ -74,7 +74,11 @@
     "Show related videos: ": "Προβολή σχετικών βίντεο; ",
     "Show annotations by default: ": "Αυτόματη προβολή σημειώσεων; :",
     "Visual preferences": "Προτιμήσεις εμφάνισης",
+    "Player style: ": "",
     "Dark mode: ": "Σκοτεινή λειτουργία: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Ελαφριά λειτουργία: ",
     "Subscription preferences": "Προτιμήσεις συνδρομών",
     "Show annotations by default for subscribed channels: ": "Προβολή σημειώσεων μόνο για κανάλια στα οποία είστε συνδρομητής; ",

locales/en-US.json

@@ -74,7 +74,11 @@
     "Show related videos: ": "Show related videos: ",
     "Show annotations by default: ": "Show annotations by default: ",
     "Visual preferences": "Visual preferences",
+    "Player style: ": "",
     "Dark mode: ": "Dark mode: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Thin mode: ",
     "Subscription preferences": "Subscription preferences",
     "Show annotations by default for subscribed channels: ": "Show annotations by default for subscribed channels? ",

locales/eo.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "Ĉu montri rilatajn videojn? ",
     "Show annotations by default: ": "Ĉu montri prinotojn defaŭlte? ",
     "Visual preferences": "Vidaj preferoj",
+    "Player style: ": "",
     "Dark mode: ": "Malhela reĝimo: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Maldika reĝimo: ",
     "Subscription preferences": "Abonaj agordoj",
     "Show annotations by default for subscribed channels: ": "Ĉu montri prinotojn defaŭlte por abonitaj kanaloj? ",

locales/es.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "¿Mostrar vídeos relacionados? ",
     "Show annotations by default: ": "¿Mostrar anotaciones por defecto? ",
     "Visual preferences": "Preferencias visuales",
+    "Player style: ": "",
     "Dark mode: ": "Modo oscuro: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Modo compacto: ",
     "Subscription preferences": "Preferencias de la suscripción",
     "Show annotations by default for subscribed channels: ": "¿Mostrar anotaciones por defecto para los canales suscritos? ",

locales/eu.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "",
     "Show annotations by default: ": "",
     "Visual preferences": "",
+    "Player style: ": "",
     "Dark mode: ": "",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "",
     "Subscription preferences": "",
     "Show annotations by default for subscribed channels: ": "",

locales/fr.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "Voir les vidéos liées : ",
     "Show annotations by default: ": "Voir les annotations par défaut : ",
     "Visual preferences": "Préférences du site",
+    "Player style: ": "",
     "Dark mode: ": "Mode Sombre : ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Mode Simplifié : ",
     "Subscription preferences": "Préférences de la page d'abonnements",
     "Show annotations by default for subscribed channels: ": "Voir les annotations par défaut sur les chaînes suivies : ",

locales/is.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "Sýna tengd myndbönd? ",
     "Show annotations by default: ": "Á að sýna glósur sjálfgefið? ",
     "Visual preferences": "Sjónrænar stillingar",
+    "Player style: ": "",
     "Dark mode: ": "Myrkur ham: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Þunnt ham: ",
     "Subscription preferences": "Áskriftarstillingar",
     "Show annotations by default for subscribed channels: ": "Á að sýna glósur sjálfgefið fyrir áskriftarrásir? ",

locales/it.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "Mostra video correlati? ",
     "Show annotations by default: ": "Mostra le annotazioni per impostazione predefinita? ",
     "Visual preferences": "Preferenze grafiche",
+    "Player style: ": "",
     "Dark mode: ": "Tema scuro: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Modalità per connessioni lente: ",
     "Subscription preferences": "Preferenze iscrizioni",
     "Show annotations by default for subscribed channels: ": "",

locales/nb_NO.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "Vis relaterte videoer? ",
     "Show annotations by default: ": "Vis merknader som forvalg? ",
     "Visual preferences": "Visuelle innstillinger",
+    "Player style: ": "",
     "Dark mode: ": "Mørk drakt: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Tynt modus: ",
     "Subscription preferences": "Abonnementsinnstillinger",
     "Show annotations by default for subscribed channels: ": "Vis merknader som forvalg for kanaler det abonneres på? ",

locales/nl.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "Gerelateerde video's tonen? ",
     "Show annotations by default: ": "Standaard annotaties tonen? ",
     "Visual preferences": "Visuele instellingen",
+    "Player style: ": "",
     "Dark mode: ": "Donkere modus: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Smalle modus: ",
     "Subscription preferences": "Abonnementsinstellingen",
     "Show annotations by default for subscribed channels: ": "Standaard annotaties tonen voor geabonneerde kanalen? ",

locales/pl.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "Pokaż powiązane filmy? ",
     "Show annotations by default: ": "",
     "Visual preferences": "Preferencje Wizualne",
+    "Player style: ": "",
     "Dark mode: ": "Ciemny motyw: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Tryb minimalny: ",
     "Subscription preferences": "Preferencje subskrybcji",
     "Show annotations by default for subscribed channels: ": "",

locales/ru.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "Показывать похожие видео? ",
     "Show annotations by default: ": "Всегда показывать аннотации? ",
     "Visual preferences": "Настройки сайта",
+    "Player style: ": "",
     "Dark mode: ": "Тёмное оформление: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Облегчённое оформление: ",
     "Subscription preferences": "Настройки подписок",
     "Show annotations by default for subscribed channels: ": "Всегда показывать аннотации в видео каналов, на которые вы подписаны? ",

locales/uk.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "Показувати схожі відео? ",
     "Show annotations by default: ": "Завжди показувати анотації? ",
     "Visual preferences": "Налаштування сайту",
+    "Player style: ": "",
     "Dark mode: ": "Темне оформлення: ",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "Полегшене оформлення: ",
     "Subscription preferences": "Налаштування підписок",
     "Show annotations by default for subscribed channels: ": "Завжди показувати анотації у відео каналів, на які ви підписані? ",

locales/zh-CN.json

@@ -68,7 +68,11 @@
     "Show related videos: ": "显示相关视频？",
     "Show annotations by default: ": "默认显示视频注释？",
     "Visual preferences": "视觉选项",
+    "Player style: ": "",
     "Dark mode: ": "暗色模式：",
+    "Theme: ": "",
+    "dark": "",
+    "light": "",
     "Thin mode: ": "窄页模式：",
     "Subscription preferences": "订阅设置",
     "Show annotations by default for subscribed channels: ": "在订阅频道的视频默认显示注释？",