Various keyboard accessibility improvements

Reason for the change

Fixes some keyboard accessibility issues

Test plan

1. Press "Highlight Entry" in mobile mode. Before: listview moved but entry was not highlighted. Now: entry is highlighted
2. Give focus to mobile playlist and keep pressing tab. Before: overflow button for all playlist entries were taking focus. Now: only the button for the active entry takes focus
3. (Desktop mode) Hide playlist and then press tab a lot of times. Before: invisible playlist took keyboard focus. Now: invisible playlist is ignored by focus.
4. Enter party mode and press tab a lot of times. Before: invisible main content view took keyboard focus. Now: invisible main content view is ignored by focus.
5. Open the Now Playing page and press tab a few times. Before: invisible button took keyboard focus. Now: invisible button ignored by focus.
6. Give focus to the Metadata and Lyrics buttons in the Now Playing view and press enter. The focussed button should always be checked after pressing enter. There will always be 1 button checked since they are in an exclusive group.
7. Set rating style to favorites. Then focus the Only Show Favorites filter button and press enter. The button should toggle/untoggle and the onToggled signal is called.
8. Give focus to volume slider. Use the left/right arrow keys. Scroll the mouse wheel above the sliders. Move the sliders with the mouse. All work as expected.
9. Give focus to duration slider. Use the left/right arrow keys. Scroll the mouse wheel above the sliders. Move the sliders with the mouse. All work as expected.