Reply rendering (#861)

* Cleanup how we use message timeline items in preparation for rich reply rendering

* Expose reply details up to the UI level

* Render replies in the timeline (textual for now). Remove now unused AttributedStringBuilderComponent isReply flag.

* Move reply detail loading to when the item appears instead of when it's created.

* Fix unit tests

* Fetch event details also when the reply details are in the error state

* Tweaks following code review

* Localise emote bodies

* Fix replies not loading sometimes, use the current event identifier instead of the one being replied to

ElementX/Sources/Services/Timeline/TimelineItems/Items/Messages/ImageRoomTimelineItem.swift

@@ -17,22 +17,21 @@
 import UIKit
 import UniformTypeIdentifiers
 
-struct ImageRoomTimelineItem: EventBasedTimelineItemProtocol, Identifiable, Hashable {
+struct ImageRoomTimelineItem: EventBasedMessageTimelineItemProtocol, Identifiable, Hashable {
     let id: String
-    let body: String
     let timestamp: String
     let isOutgoing: Bool
     let isEditable: Bool
     
     let sender: TimelineItemSender
     
-    let source: MediaSourceProxy
+    let content: ImageRoomTimelineItemContent
     
-    var width: CGFloat?
-    var height: CGFloat?
-    var aspectRatio: CGFloat?
-    var blurhash: String?
-    var contentType: UTType?
+    var replyDetails: TimelineItemReplyDetails?
     
     var properties = RoomTimelineItemProperties()
+    
+    var body: String {
+        content.body
+    }
 }