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

DesignKit/Source/ThemeV2.swift

@@ -21,11 +21,23 @@ import UIKit
 @objc public protocol ThemeV2 {
     
     /// Colors object
-    var colors: Colors { get }
+    var colors: ColorsUIKit { get }
     
     /// Fonts object
-    var fonts: Fonts { get }
+    var fonts: FontsUIKit { get }
+    
+    /// may contain more design components in future, like icons, audio files etc.
+}
+
+/// Theme v2 for SwiftUI.
+@available(iOS 14.0, *)
+public protocol ThemeSwiftUIType {
+    
+    /// Colors object
+    var colors: ColorSwiftUI { get }
+    
+    /// Fonts object
+    var fonts: FontSwiftUI { get }
     
     /// may contain more design components in future, like icons, audio files etc.
-    
 }