Make tvOS detail dismiss button opt-in and unstick more views

TVSidebarDetailContainer now exposes a showsDismissButton flag instead of
always attaching a Done toolbar item. The button is only enabled where a
view can end up with no focusable element on its own — Device
Capabilities (informational rows) and the Import Playlists/Subscriptions
flows.

Wrap Contributors, Translators, Acknowledgements, and Device Capabilities
destinations in TVSidebarDetailContainer for the consistent sidebar look,
and make the Translators/Acknowledgements rows focusable on tvOS by
wrapping them in Buttons so the Menu remote button can pop the stack.

Yattee/Views/Settings/TranslationContributorsView.swift

@@ -47,6 +47,16 @@ struct TranslationContributorsView: View {
     }
 
     private func contributorRow(_ contributor: TranslationContributor) -> some View {
+        #if os(tvOS)
+        Button {} label: {
+            contributorRowContent(contributor)
+        }
+        #else
+        contributorRowContent(contributor)
+        #endif
+    }
+
+    private func contributorRowContent(_ contributor: TranslationContributor) -> some View {
         HStack(spacing: 12) {
             // Avatar
             LazyImage(url: contributor.gravatarURL) { state in