Allow the user to forward the same message to multiple rooms at once

This will send the item to the rooms in order they were chosen and only deep link
into the target room if single, otherwise it will just dismiss the forwarding screen
after sending.

ElementX/Sources/Screens/MessageForwardingScreen/View/MessageForwardingScreen.swift

@@ -17,7 +17,7 @@ struct MessageForwardingScreen: View {
             Section {
                 ForEach(context.viewState.rooms) { room in
                     MessageForwardingListRow(room: room,
-                                             isSelected: context.viewState.selectedRoomID == room.id,
+                                             isSelected: context.viewState.selectedRoomIDs.contains(room.id),
                                              context: context)
                 }
                 // Replace these with ScrollView's `scrollPosition` when dropping iOS 16.
@@ -46,7 +46,7 @@ struct MessageForwardingScreen: View {
                 Button(L10n.actionSend) {
                     context.send(viewAction: .send)
                 }
-                .disabled(context.viewState.selectedRoomID == nil)
+                .disabled(context.viewState.selectedRoomIDs.isEmpty)
             }
         }
         .searchController(query: $context.searchQuery, showsCancelButton: false)