Read Receipts display with the user avatar (#1038)

* added the read receipt into the code

* fixed some things lost during merge

* implemented the status view to be always at the trailing side

* preview code for better testing

* removed timelineStyle modifier

* removed also the group style

* added some UI tests for the read receipts

ElementX/Sources/Screens/RoomScreen/RoomScreenModels.swift

@@ -77,10 +77,12 @@ struct RoomScreenViewState: BindableState {
     var roomTitle = ""
     var roomAvatarURL: URL?
     var items: [RoomTimelineViewProvider] = []
+    var members: [String: RoomMemberState] = [:]
     var canBackPaginate = true
     var isBackPaginating = false
     var showLoading = false
     var timelineStyle: TimelineStyle
+    var readReceiptsEnabled: Bool
     
     var bindings: RoomScreenViewStateBindings
     
@@ -123,3 +125,8 @@ enum RoomScreenErrorType: Hashable {
     /// A specific error message shown in a toast.
     case toast(String)
 }
+
+struct RoomMemberState {
+    let displayName: String?
+    let avatarURL: URL?
+}