Move NeoChatRoom::showMessage to Controller

It doesn't fit into NeoChatRoom conceptually

src/neochatroom.h

@@ -206,16 +206,6 @@ class NeoChatRoom : public Quotient::Room
 #endif
 
 public:
-    /**
-     * @brief Define the types on inline messages that can be shown.
-     */
-    enum MessageType {
-        Positive, /**< Positive message, typically green. */
-        Info, /**< Info message, typically highlight color. */
-        Error, /**< Error message, typically red. */
-    };
-    Q_ENUM(MessageType)
-
     explicit NeoChatRoom(Quotient::Connection *connection, QString roomId, Quotient::JoinState joinState = {});
 
     [[nodiscard]] QDateTime lastActiveTime();
@@ -642,7 +632,6 @@ Q_SIGNALS:
     void readOnlyChanged();
     void displayNameChanged();
     void pushNotificationStateChanged(PushNotificationState::State state);
-    void showMessage(MessageType messageType, const QString &message);
     void canEncryptRoomChanged();
     void joinRuleChanged();
     void historyVisibilityChanged();