Prevent invalid composer mode crashes

Cause by voice recording racing against the send action.

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

@@ -189,6 +189,8 @@ final class ComposerToolbarViewModel: ComposerToolbarViewModelType, ComposerTool
             switch state.composerMode {
             case .previewVoiceMessage:
                 actionsSubject.send(.voiceMessage(.send))
+            case .recordVoiceMessage:
+                MXLog.warning("Ignoring send action while recording a voice message.")
             default:
                 if context.composerFormattingEnabled {
                     actionsSubject.send(.sendMessage(plain: wysiwygViewModel.content.markdown,

ElementX/Sources/Screens/Timeline/TimelineViewModel.swift

@@ -807,7 +807,8 @@ class TimelineViewModel: TimelineViewModelType, TimelineViewModelProtocol {
                                                      intentionalMentions: intentionalMentions)
             }
         case .recordVoiceMessage, .previewVoiceMessage:
-            fatalError("invalid composer mode.")
+            MXLog.error("Ignoring sendCurrentMessage with invalid composer mode: \(mode)")
+            return
         }
         
         scrollToBottom()