Ensure that first start machine actions model gets initialized

CURA-6932

cura/CuraApplication.py

@@ -880,6 +880,8 @@ class CuraApplication(QtApplication):
     def getFirstStartMachineActionsModel(self, *args) -> "FirstStartMachineActionsModel":
         if self._first_start_machine_actions_model is None:
             self._first_start_machine_actions_model = FirstStartMachineActionsModel(self, parent = self)
+            if self.started:
+                self._first_start_machine_actions_model.initialize()
         return self._first_start_machine_actions_model
 
     @pyqtSlot(result = QObject)

cura/Machines/Models/FirstStartMachineActionsModel.py

@@ -33,11 +33,11 @@ class FirstStartMachineActionsModel(ListModel):
         self._current_action_index = 0
 
         self._application = application
-        self._application.initializationFinished.connect(self._initialize)
+        self._application.initializationFinished.connect(self.initialize)
 
         self._previous_global_stack = None
 
-    def _initialize(self) -> None:
+    def initialize(self) -> None:
         self._application.getMachineManager().globalContainerChanged.connect(self._update)
         self._update()