Video playback (#308)

* Create media player screen

* Introduce `FileCache` to cache message attachments

* Add file loading functionality into the media provider

* Process tap action on timeline items

* Pass item taps to view model

* Navigate to media player on view model callback

* Commit project file

* Add changelog

* Rename media to video

* Add a loader when large videos being processed

* Add back button explicitly on video screen, fixes for light scheme

* Handle right swipe to dismiss video

ElementX/Sources/Screens/RoomScreen/RoomScreenModels.swift

@@ -17,7 +17,9 @@
 import Foundation
 import UIKit
 
-enum RoomScreenViewModelAction { }
+enum RoomScreenViewModelAction {
+    case displayVideo(videoURL: URL)
+}
 
 enum RoomScreenComposerMode: Equatable {
     case `default`
@@ -29,6 +31,7 @@ enum RoomScreenViewAction {
     case loadPreviousPage
     case itemAppeared(id: String)
     case itemDisappeared(id: String)
+    case itemTapped(id: String)
     case linkClicked(url: URL)
     case sendMessage
     case sendReaction(key: String, eventID: String)
@@ -42,6 +45,7 @@ struct RoomScreenViewState: BindableState {
     var roomAvatar: UIImage?
     var items: [RoomTimelineViewProvider] = []
     var isBackPaginating = false
+    var showLoading = false
     var bindings: RoomScreenViewStateBindings
     
     var contextMenuBuilder: (@MainActor (_ itemId: String) -> TimelineItemContextMenu)?