feat: create stream and add members to stream

src/MainWindow.h

@@ -18,6 +18,8 @@ class QLabel;
 QT_END_NAMESPACE
 
 class AuthDialog;
+class CreateStreamDialog;
+class MemberPickerDialog;
 class SettingsDialog;
 class TextInputDialog;
 
@@ -62,6 +64,7 @@ private:
 
   SettingsDialog *m_settingsDialog;
   TextInputDialog *m_textInputDialog;
+  CreateStreamDialog *m_createStreamDialog;
 
   // Data and models
   Store *m_store;