Media loading flow changes (#483)

* Use an imageProvider directly from the view in the home screen

* Add support for media request coalescing

* Rename MediaProxy to MediaLoader

* Add new image loading mechanism to the room details screen avatar.

* Use the `SettingsScreen` prefix for all settings screen related components

* Add new image loading mechanism to the room header

* Add new image loading mechanism to the room member details screen

* Introduce a LoadableImage SwiftUI view that will automatically handle image loading

* Adopt the new LoadableImage where possible

* Fix LoadableImage not using/storing loaded images properly

* Simplify media loader enqueueing

* Made LodableImage load content after mediaSource updates. Adopt it on the home and settings screens

* Introduce a LoadableAvatarImage component and reuse it throughout the app

* Small logging tweaks, made some LoadableImage properties private

* Fix redacted skeletons avatar background color

* Fix placeholder avatars changing when backgrounding the app

* PR comments.

- Trim the @ sign off of mxid placeholders.
- Only expose AvatarSize on the avatar image, use CGSize elsewhere.

Co-authored-by: Doug <douglase@element.io>

NSE/Sources/NotificationServiceExtension.swift

@@ -125,15 +125,15 @@ class NotificationServiceExtension: UNNotificationServiceExtension {
 
         let client = try builder.build()
         try client.restoreSession(session: credentials.restorationToken.session)
-
+        
         MXLog.info("\(tag) creating media provider")
-
-        return MediaProvider(mediaProxy: MediaProxy(client: client),
+        
+        return MediaProvider(mediaLoader: MediaLoader(client: client),
                              imageCache: .onlyOnDisk,
                              fileCache: FileCache.default,
                              backgroundTaskService: nil)
     }
-
+    
     private func notify() {
         MXLog.info("\(tag) notify")