Accessibility fixes and improvements

[amugofjava]

Describe the bug
This is a tracking issue for accessibility enhancements and fixes to work on. Please add comments to this issue if there are additional issues that should be worked on and are missing from this list.

Settings

• Missing heading attribute.
• Toggle switches - merge semantics between text and switch to reduce swipes required.
• Search provider dialog missing close button.

Library

• Layout selector missing barrierLabel - says 'scrim'.
• Layout selector not reading currently selected layout.
• Episode tile
  • Android: Replace expanded tile with dialog menu when screen reader enabled.
  • iOS: Replace expanded tile with Cupertino menu when screen reader enabled.

Episode list page

• Episode tile missing semantic button label.
• More info bottom sheet missing barrierLabel - says 'scrim'
• Go back button does not say 'button'. Missing button attribute.
• Unfollow dialog buttons un-labelled.
• Podcast funding dialog missing heading semantic.
• Sort episodes
  • Missing barrierLabel - says 'scrim'
  • Missing does not read currently selected item.
• Filter episodes
  • Missing barrierLabel - says 'scrim'
  • Missing does not read currently selected item.

Player window

• Player window contents read twice on form open.
• Current & remaining time missing semantic labels.
• Fast forward button missing semantic label.
• Up next queue cannot be re-ordered via VoiceOver.