Use workspaceLoaded signal instead of projectFileLoaded

CURA-4581

cura/CuraApplication.py

@@ -126,8 +126,6 @@ class CuraApplication(QtApplication):
     #        Cura will always show the Add Machine Dialog upon start.
     stacksValidationFinished = pyqtSignal()  # Emitted whenever a validation is finished
 
-    projectFileLoaded = pyqtSignal(str)  # Emitted whenever a project file is loaded
-
     def __init__(self):
         # this list of dir names will be used by UM to detect an old cura directory
         for dir_name in ["extruders", "machine_instances", "materials", "plugins", "quality", "user", "variants"]:

cura/PrintInformation.py

@@ -71,7 +71,7 @@ class PrintInformation(QObject):
 
         Application.getInstance().globalContainerStackChanged.connect(self._updateJobName)
         Application.getInstance().fileLoaded.connect(self.setBaseName)
-        Application.getInstance().projectFileLoaded.connect(self.setProjectName)
+        Application.getInstance().workspaceLoaded.connect(self.setProjectName)
         Preferences.getInstance().preferenceChanged.connect(self._onPreferencesChanged)
 
         self._active_material_container = None