tombstoned and upgraded rooms implementation

added tests

tombstoned room avatar

ElementX/Sources/Services/Room/RoomInfoProxy.swift

@@ -33,6 +33,10 @@ struct RoomInfoProxy: BaseRoomInfoProxyProtocol {
     var avatarURL: URL? { roomInfo.avatarUrl.flatMap(URL.init) }
     /// The room's avatar info for use in a ``RoomAvatarImage``.
     var avatar: RoomAvatar {
+        guard successor == nil else {
+            return .tombstoned
+        }
+        
         if isDirect, avatarURL == nil, heroes.count == 1 {
             return .heroes(heroes.map(UserProfileProxy.init))
         }
@@ -61,7 +65,7 @@ struct RoomInfoProxy: BaseRoomInfoProxyProtocol {
     }
     
     var isSpace: Bool { roomInfo.isSpace }
-    var tombstoneInfo: SuccessorRoom? { roomInfo.successorRoom }
+    var successor: SuccessorRoom? { roomInfo.successorRoom }
     var isFavourite: Bool { roomInfo.isFavourite }
     var canonicalAlias: String? { roomInfo.canonicalAlias }
     var alternativeAliases: [String] { roomInfo.alternativeAliases }