Enable the media browser feature 🖼️ (#3642)

* Overlay a progress indicator for downloads instead of using a toast indicator.

* Update the SDK.

* Remove the feature flag for the media browser.

* Remove the media captions feature flag too.

* Add unit test cases for download failure and swiping between items.

* Snapshots (with the media browser visible in the screen).

ElementX/Sources/Screens/Settings/DeveloperOptionsScreen/DeveloperOptionsScreenModels.swift

@@ -50,8 +50,6 @@ protocol DeveloperOptionsProtocol: AnyObject {
     var enableOnlySignedDeviceIsolationMode: Bool { get set }
     var elementCallBaseURLOverride: URL? { get set }
     var knockingEnabled: Bool { get set }
-    var createMediaCaptionsEnabled: Bool { get set }
-    var mediaBrowserEnabled: Bool { get set }
     var eventCacheEnabled: Bool { get set }
 }