Hook now playing sidebar button to fullscreen

This properly selects the correct fullscreen mode.

Fixes plexinc/plex-home-theater#1166
A simple panel based mixed video thumb pq list.
Fix tab button from VideoOSD

This also restores the videoOSD when the fullscreen window is opened
and the video is paused.
Fix VideoPlayer.AudioStream and SubtitleStream

We need to get them from g_application instead of guiinfomanager
because they will differ.
Don't re-resolve items in MDE.

This might have lead to problems with restarting the same stream.
Toast when playing a new video

Fixes #1156
Add System.PlexPlayQueue

Takes the following arguments: music, video or any and will return true
if the current PlayQueue is the type. Note that this doesn’t say
anything about if the current play queue is playing or not.

Fixes #1167
Added System.PlexPlayQueue to debug overlay.
Fix return to PlayQueue window

This the path of the PlayQueue container could contain the path we used
to create the playQueue from the start. Which is obviously not right.
So instead we override that with plexserver://playqueue/
PiP in pq window.
Add buttons for navigating between pq and fullscreen video player.
Fix modality of the videoOSD
Fade pq OSD while in PiP player.
Disable mini player strip for now.
Add Play/Shuffle All actions to Photos. Part of plexinc/plex-home-theater#1164
[FIX] Avoid checking local PMS on RPi

This allows to avoid the error message saying that it wasn't found as we obviously will never have any PMS running on RPi.
Fix Channels video content pq.
Add PQ specifics to debug layer.
Add SourceIcon to clip content pq thumbs when exists.
Fix crashes in IsXContainer

Need to check that m_vecItems contains something.