Use a simple menubar for addcards on macOS

This makes initial-open and reopen behaviour consistent.

Closes #3659

qt/aqt/addcards.py

@@ -57,7 +57,8 @@ class AddCards(QMainWindow):
         gui_hooks.operation_did_execute.append(self.on_operation_did_execute)
         restoreGeom(self, "add")
         gui_hooks.add_cards_did_init(self)
-        self.setMenuBar(None)
+        if not is_mac:
+            self.setMenuBar(None)
         self.show()
 
     def set_deck(self, deck_id: DeckId) -> None:

qt/aqt/forms/addcards.ui

@@ -91,6 +91,12 @@
      <height>22</height>
     </rect>
    </property>
+   <widget class="QMenu" name="menu_Edit">
+    <property name="title">
+     <string>qt_accel_edit</string>
+    </property>
+   </widget>
+   <addaction name="menu_Edit"/>
   </widget>
  </widget>
  <resources>