Little refactors (apply review comments). [CURA-6294]

cura/CuraApplication.py

@@ -453,7 +453,6 @@ class CuraApplication(QtApplication):
             # Misc.:
             "ConsoleLogger", #You want to be able to read the log if something goes wrong.
             "CuraEngineBackend", #Cura is useless without this one since you can't slice.
-            # NOTE: User-Agreement is part of the 'onboarding flow' now (See Welcome Pages).
             "FileLogger", #You want to be able to read the log if something goes wrong.
             "XmlMaterialProfile", #Cura crashes without this one.
             "Toolbox", #This contains the interface to enable/disable plug-ins, so if you disable it you can't enable it back.

cura/UI/WelcomePagesModel.py

@@ -7,7 +7,6 @@ from PyQt5.QtCore import QUrl, Qt
 
 from UM.Qt.ListModel import ListModel
 from UM.Resources import Resources
-from logging import Logger
 
 if TYPE_CHECKING:
     from PyQt5.QtCore import QObject

resources/qml/Cura.qml

@@ -78,13 +78,13 @@ UM.MainWindow
         {
             welcomeDialog.visible = true;
             welcomeDialog.currentStep = 0;
-            welcomeDialog.show();
         }
         else
         {
-            welcomeDialog.hide()
             welcomeDialog.visible = false;
         }
+        // TODO: While the new onboarding process contains the user-agreement,
+        //       it should probably not entirely rely on 'needToShowUserAgreement' for show/hide.
     }
 
     Item