Draft: Add voip call functionality

• Outgoing calls: Test against:
  • Element Web
  • Element Android
  • Nheko
  • NeoChat
• Incoming Calls: Test against:
  • Element Web
  • Element Android
  • Nheko
  • NeoChat
• Video Feed
  • Incoming
    • Show Video
    • Handle renegotiation
    • Handle disabled (is that a thing?)
  • Outgoing
    • Send Video
    • Allow changing and disabling Video Device
    • Allow Screen Sharing
      • X11
      • Wayland
      • (Windows)
      • (Android?)
    • Send stream identifier thing
  • Audio Feed
    • Send
    • Receive
    • Mute
    • Show Remote muted (do we know this?)
    • Audio source selector
• UI
  • Outgoing
    • Button on room page
    • Configure Video, Audio Devices
      • Default Device, Settings page
      • Ringtone
    • Call Screen
  • Incoming
    • Notification
    • InlineMessage
  • Ongoing call
  • Show videos
  • Allow showing video fullscreen
  • Muting
• Glare