Do avatar placeholder in SwiftUI, Add AvatarViewModel, Add dependency injection for MxMediaManager dependency.

Riot/Modules/Room/NotificationSettings/RoomNotificationState.swift

@@ -27,3 +27,16 @@ extension RoomNotificationState: CaseIterable { }
 extension RoomNotificationState: Identifiable {
     var id: Int { self.rawValue }
 }
+
+extension RoomNotificationState {
+    var title: String {
+        switch self {
+        case .all:
+            return VectorL10n.roomNotifsSettingsAllMessages
+        case .mentionsAndKeywordsOnly:
+            return VectorL10n.roomNotifsSettingsMentionsAndKeywords
+        case .mute:
+            return VectorL10n.roomNotifsSettingsNone
+        }
+    }
+}