Some Post-demo Cleanups (#200)

* Remove redundant string

* Use placeholder avatar on home screen

* Add initial home screen ui test

* Fix settings screen PR remarks

* Remove UIKit alert from home screen sign out

* Remove UIKit alert from soft logout clear all data

* Add reference screenshots for home screen UI tests

* Formatting fixes

* Add clearing room method to client proxy

* Clear room proxies on screen dismiss

* Fix retain cycle in room view model

* Do not go into authentication state immediately

* Define sizes for user and room avatars on different screens

* Use defined avatar sizes everywhere

* Disable image disk caching

* Rename rounded corner shape

* Fix text color of placeholder avatars

* Fix PR reviews on formatted body text

* Fix merge conflict

* Remove shouldShowSenderDetails everywhere and just use it from inGroupState

* Remove redundant linter disablings

* Fix PR remarks

* Rename media provider size parameter

ElementX/Sources/Screens/RoomScreen/View/RoomHeaderView.swift

@@ -42,7 +42,7 @@ struct RoomHeaderView: View {
                     .accessibilityIdentifier("encryptionBadgeIcon")
             }
         }
-        .frame(width: 32.0, height: 32.0)
+        .frame(width: AvatarSize.room(on: .timeline).value, height: AvatarSize.room(on: .timeline).value)
     }
 
     @ViewBuilder private var roomAvatarImage: some View {