Add support for sending media within threads.

This patch add the `threadRootEventID` as a parameter to media sending functions and forwards the timeline thread root between various application states to the place where its needed.
The 2 missing items are Locations and Polls which currently don't have any support on the Rust side for being sent within threads. That will come in a separate PR.

ElementX/Sources/Screens/RoomScreen/ComposerToolbar/ComposerToolbarViewModel.swift

@@ -46,6 +46,7 @@ final class ComposerToolbarViewModel: ComposerToolbarViewModelType, ComposerTool
 
     init(initialText: String? = nil,
          roomProxy: JoinedRoomProxyProtocol,
+         isInThread: Bool = false,
          wysiwygViewModel: WysiwygComposerViewModel,
          completionSuggestionService: CompletionSuggestionServiceProtocol,
          mediaProvider: MediaProviderProtocol,
@@ -68,6 +69,7 @@ final class ComposerToolbarViewModel: ComposerToolbarViewModelType, ComposerTool
                                                               audioRecorderState: .init(),
                                                               isRoomEncrypted: roomProxy.infoPublisher.value.isEncrypted,
                                                               isLocationSharingEnabled: appSettings.mapTilerConfiguration.isEnabled,
+                                                              isInThread: isInThread,
                                                               bindings: .init()),
                    mediaProvider: mediaProvider)