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/RoomScreenViewModel.swift

@@ -89,6 +89,10 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
             MXLog.warning("React with \(key) failed. Not implemented.")
         case .cancelReply:
             state.composerMode = .default
+        case .viewDisappeared:
+            cancellables.forEach { $0.cancel() }
+            cancellables.removeAll()
+            state.contextMenuBuilder = nil
         }
     }