We don't want the user to be able to save any state of the bridge to prevent incomplete or potentially faulty edits to occur on Wikidata and to prevent a system error in advance. Therefore we have to disable the save button for some of the states.
the disabled state should be ButtonWidget (progressive, disabled) looking like this (button in the top right corner)
- Save button is disabled when nothing has been changed yet
- header height is correct (40px) and disabled save button uses the full header height