MPV: improved A/V sync

- use displays refresh rate
- execute needs drawing with higher priority
- run create() with higher priority
- determine the number of threads used for rendering
- enable VSYNC and change video-sync  to display-resample
- iOS/tvOS: set new display refresh rate on change
- run setSize with higher priority
- add more options to MPVClient
- get refresh rate updates
- sync refresh rate to fps
- update CADisplayLink to current refresh rate
- update refresh rate on macOS
- Add experimental feature to sync display  with content fps

Signed-off-by: Toni Förster <toni.foerster@gmail.com>

Model/Player/PlayerModel.swift

@@ -532,8 +532,8 @@ final class PlayerModel: ObservableObject {
     }
 
     private func handlePresentationChange() {
-        #if !os(iOS)
-            // TODO: Check whether this is neede on tvOS and macOS
+        #if os(macOS)
+            // TODO: Check whether this is needed on macOS
             backend.setNeedsDrawing(presentingPlayer)
         #endif
 
@@ -1007,23 +1007,21 @@ final class PlayerModel: ObservableObject {
         }
     #else
         func handleEnterForeground() {
+            DispatchQueue.global(qos: .userInteractive).async { [weak self] in
+                guard let self = self else { return }
+
+                if !self.musicMode, self.activeBackend == .mpv {
+                    self.mpvBackend.addVideoTrackFromStream()
+                    self.mpvBackend.setVideoToAuto()
+                    self.mpvBackend.controls.resetTimer()
+                } else if !self.musicMode, self.activeBackend == .appleAVPlayer {
+                    self.avPlayerBackend.bindPlayerToLayer()
+                }
+            }
             #if os(iOS)
                 OrientationTracker.shared.startDeviceOrientationTracking()
             #endif
 
-            #if os(tvOS)
-                // TODO: Not sure if this is realy needed on tvOS, maybe it can be removed.
-                setNeedsDrawing(presentingPlayer)
-            #endif
-
-            if !musicMode, activeBackend == .mpv {
-                mpvBackend.addVideoTrackFromStream()
-                mpvBackend.setVideoToAuto()
-                mpvBackend.controls.resetTimer()
-            } else if !musicMode, activeBackend == .appleAVPlayer {
-                avPlayerBackend.bindPlayerToLayer()
-            }
-
             guard closePiPAndOpenPlayerOnEnteringForeground, playingInPictureInPicture else {
                 return
             }