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/View/NotificationSettingsKeywords.swift

@@ -0,0 +1,46 @@
+// 
+// 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 SwiftUI
+
+/**
+ Renders the keywords input, driven by 'NotificationSettingsViewModel'.
+ */
+@available(iOS 14.0, *)
+struct NotificationSettingsKeywords: View {
+    @ObservedObject var viewModel: NotificationSettingsViewModel
+    var body: some View {
+        ChipsInput(
+            titles: viewModel.viewState.keywords,
+            didAddChip: viewModel.add(keyword:),
+            didDeleteChip: viewModel.remove(keyword:),
+            placeholder: VectorL10n.settingsNewKeyword
+        )
+        .disabled(!(viewModel.viewState.selectionState[.keywords] ?? false))
+
+    }
+}
+
+@available(iOS 14.0, *)
+struct Keywords_Previews: PreviewProvider {
+    static let viewModel = NotificationSettingsViewModel(
+        notificationSettingsService: MockNotificationSettingsService.example,
+        ruleIds: NotificationSettingsScreen.mentionsAndKeywords.pushRules
+    )
+    static var previews: some View {
+        NotificationSettingsKeywords(viewModel: viewModel)
+    }
+}