Layout and PiP improvements, new settings

- player is now a separate window on macOS
- add setting to disable pause when player is closed (fixes #40)
- add PiP settings:
  * Close PiP when starting playing other video
  * Close PiP when player is opened
  * Close PiP and open player when application
    enters foreground (iOS/tvOS) (fixes #37)
- new player placeholder when in PiP, context menu with exit option

Shared/Player/PlayerQueueRow.swift

@@ -1,3 +1,4 @@
+import Defaults
 import Foundation
 import SwiftUI
 
@@ -8,6 +9,8 @@ struct PlayerQueueRow: View {
 
     @EnvironmentObject<PlayerModel> private var player
 
+    @Default(.closePiPOnNavigation) var closePiPOnNavigation
+
     var body: some View {
         Group {
             Button {
@@ -24,6 +27,10 @@ struct PlayerQueueRow: View {
                         fullScreen = false
                     }
                 }
+
+                if closePiPOnNavigation, player.playingInPictureInPicture {
+                    player.closePiP()
+                }
             } label: {
                 VideoBanner(video: item.video, playbackTime: item.playbackTime, videoDuration: item.videoDuration)
             }