Finish extraction

- Moves SwiftUI code out of Riot and into RiotSwiftUI which has no dependency on Matrix SDK.
- Git wasn't smart enough to see the file moves. Most feature function has remain unchanged. 1 change I did make was remove NotificationSettingsViewModel's dependence on MxPushRule, so that the view model could be moved into RiotSwiftUI.
- Add LocaleProvider to abstract VectorL10n's use of Matrix SDK language so it can be used in RiotSwiftUI.
- Split Theme into UKit/SwiftUI version to remove RiotSwiftUI's dependence on ThemeService and ThemeV1.
- Migrated from ThemeObserver to ThemePublisher. We push updates to ThemePublisher so that we can remove ThemeService as dependency.
- Add .DS_Store to .gitignore

RiotSwiftUI/Modules/Room/NotificationSettings/Model/RoomNotificationState.swift

@@ -0,0 +1,42 @@
+// 
+// Copyright 2021 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+
+enum RoomNotificationState: Int {
+    case all
+    case mentionsAndKeywordsOnly
+    case mute
+}
+
+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
+        }
+    }
+}