Check and apply/remove TV mode UI on the fly when switching monitors.
This allows for e.g. having a mobile device connected to external big screen,
drag Clapper window from one screen to another and UI should automatically
adapt between mobile and TV modes without interrupting playback.
This also helps in situations where monitor size is not initially known
on window map #74.
Start app with the correct controls layout instead of showing the "hide elapsed time"
transition when started on mobile width. It is annoying.
We cannot detect surface width during app widgets assembly, so update the controls
revealers state on first surface update after window is mapped and only if running
on mobile width. Otherwise do not do anything like before which will result in
showing fully revealed controls (default).
The window size was restored too early which caused the window to be a little bigger then it should on each launch. Restore window size after that window was mapped.
Play video with external subtiles by:
* selecting and opening both video+subs from file chooser/manager
* dropping subtitles file on player window
* opening subtiles from file chooser/manager while video plays
* send their file path/uri to player via WebSocket message
Emit media info updated signal only when media info is initially created and when number/format of tracks changes later. This is needed for GUI to detect resolution change (adaptive streaming) or when user adds external subtitles to current video.
Changing transition in middle or when not fully revealed has dire consequences, seems to be a GTK4 bug. Workaround this bug by switching top revealer transition type only when fully revealed.
Bottom revealer motion controller was causing timeout to be cleared. Prevent that by making it child invisible when windowed, which will remove its allocated height and motion events will not be emitted.
Instead of setting hide controls timeout immediately when starting revealing, make the time controls are revealed constant by setting timeout after animation finishes.
Now that player API itself is operating on a cubic scale (no value conversion required), the volume slider can be bind to the volume property. Thanks to that, player volume scale will correctly reflect Clapper volume set via external applications e.g. gnome-settings.
Fullscreen bottom controls panel does not look good when progress bar is too long (especially on "ultrawide" displays), so limit its max width to 1720 application-pixels. This should make it still long enough for convenient chapter seeking.
