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/Settings/Notifications/Model/NotificationSettingsScreen.swift

@@ -0,0 +1,48 @@
+// 
+// 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
+
+/**
+The notification settings screen definitions, used when calling the coordinator.
+ */
+@objc enum NotificationSettingsScreen: Int {
+    case defaultNotifications
+    case mentionsAndKeywords
+    case other
+}
+
+extension NotificationSettingsScreen: CaseIterable { }
+
+extension NotificationSettingsScreen: Identifiable {
+    var id: Int { self.rawValue }
+}
+
+extension NotificationSettingsScreen {
+    /**
+     Defines which rules are handled by each of the screens.
+     */
+    var pushRules: [NotificationPushRuleId] {
+        switch self {
+        case .defaultNotifications:
+            return [.oneToOneRoom, .allOtherMessages, .oneToOneEncryptedRoom, .encrypted]
+        case .mentionsAndKeywords:
+            return [.containDisplayName, .containUserName, .roomNotif, .keywords]
+        case .other:
+            return [.inviteMe, .call, .suppressBots, .tombstone]
+        }
+    }
+}