Refactor theTimelineItemIdentifier handling; stop relying on optional EventOrTransactionIds and be explicit when setting composer modes from the draft service.

ElementX/Sources/Screens/Timeline/View/Supplementary/TimelineReactionsView.swift

@@ -196,20 +196,20 @@ struct TimelineReactionViewPreviewsContainer: View {
     var body: some View {
         VStack(spacing: 8) {
             TimelineReactionsView(context: TimelineViewModel.mock.context,
-                                  itemID: .init(uniqueID: "1"),
+                                  itemID: .randomEvent,
                                   reactions: [AggregatedReaction.mockReactionWithLongText,
                                               AggregatedReaction.mockReactionWithLongTextRTL])
             Divider()
             TimelineReactionsView(context: TimelineViewModel.mock.context,
-                                  itemID: .init(uniqueID: "2"),
+                                  itemID: .randomEvent,
                                   reactions: Array(AggregatedReaction.mockReactions.prefix(3)))
             Divider()
             TimelineReactionsView(context: TimelineViewModel.mock.context,
-                                  itemID: .init(uniqueID: "3"),
+                                  itemID: .randomEvent,
                                   reactions: AggregatedReaction.mockReactions)
             Divider()
             TimelineReactionsView(context: TimelineViewModel.mock.context,
-                                  itemID: .init(uniqueID: "4"),
+                                  itemID: .randomEvent,
                                   reactions: AggregatedReaction.mockReactions,
                                   isLayoutRTL: true)
         }

ElementX/Sources/Screens/Timeline/View/Supplementary/TimelineReadReceiptsView.swift

@@ -103,7 +103,7 @@ struct TimelineReadReceiptsView_Previews: PreviewProvider, TestablePreview {
                                    ReadReceipt(userID: RoomMemberProxyMock.mockDan.userID, formattedTimestamp: "Way, way before")]
 
     static func mockTimelineItem(with receipts: [ReadReceipt]) -> TextRoomTimelineItem {
-        TextRoomTimelineItem(id: .random,
+        TextRoomTimelineItem(id: .randomEvent,
                              timestamp: "Now",
                              isOutgoing: true,
                              isEditable: false,