[FeatureRequest] Better GamePad/TV support

[Bretterteig]

Currently the plugin cannot be controlled in TV mode by only using GamePad/Keyboard/Remote. These things would be great:

1. Add ability to close selector window
   a) By adding a close button next to the back button
   b) By capturing the backspace button click while the window is shown (might interefere with jellyfin logic)
2. Add the ability to start the selected episode via keyboard
   a) Capture return key pressed when episode is selected
   b) Make play button selectable via keyboard
3. Allow pressing favorite and watched button
   a) Navigate buttons of item with left and right arrow key. (best combined with 2b)

How to test:

1. Switch to "TV" layout by going to Profile Icon > Display > Display Mode > TV
2. Enable GamePad support Profile Icon > Controls >Enable GamePad
3. Save and reload the page. You can now control the webinterface with your keyboard. Limit yourself to arrow keys, return and backspace to best emulate the constraints of a remote (considering LG webOS uses this layout)

Small note:
The blue icon animation from JF is currenlty not applied to the plugin button