1. Fix add/play buttons missing in toolbar for YouTube Music plugin.
2. Don't allow grid for YouTube Music track lists.
3. Fix 'allplayers' custom actions appearing in app menus.
4. Fix track sources protocols list handling - thanks to bungh0110
5. Use iOS style back icons for Apple platforms.
6. Fetch custom actions for toolbar menu when clicking on search results.
7. Allow plugins to register custom actions.
8. Fix getting custom actions for cached artist and albums lists.
9. Fix custom actions for search result items.
10. Reset custom actions when browse back from 'More' on scrolled list.
11. Allow custom actions on scrolled list items.