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/Import Export Settings/Exporters/AdvancedSettingsGroupExporter.swift

@@ -13,6 +13,7 @@ final class AdvancedSettingsGroupExporter: SettingsGroupExporter {
             "mpvDeinterlace": Defaults[.mpvDeinterlace],
             "mpvHWdec": Defaults[.mpvHWdec],
             "mpvDemuxerLavfProbeInfo": Defaults[.mpvDemuxerLavfProbeInfo],
+            "mpvSetRefreshToContentFPS": Defaults[.mpvSetRefreshToContentFPS],
             "mpvInitialAudioSync": Defaults[.mpvInitialAudioSync],
             "showCacheStatus": Defaults[.showCacheStatus],
             "feedCacheSize": Defaults[.feedCacheSize]

Model/Import Export Settings/Importers/AdvancedSettingsGroupImporter.swift

@@ -41,6 +41,10 @@ struct AdvancedSettingsGroupImporter {
             Defaults[.mpvDemuxerLavfProbeInfo] = mpvDemuxerLavfProbeInfo
         }
 
+        if let mpvSetRefreshToContentFPS = json["mpvSetRefreshToContentFPS"].bool {
+            Defaults[.mpvSetRefreshToContentFPS] = mpvSetRefreshToContentFPS
+        }
+
         if let mpvInitialAudioSync = json["mpvInitialAudioSync"].bool {
             Defaults[.mpvInitialAudioSync] = mpvInitialAudioSync
         }