[Enhancement] "Save" Indicator #48
Description
When saving small files, the "Save Completed" popup occurs pretty well straight away. So, no problem...
However, for large files the saving process can take many tens of seconds and it's not obvious that anything is happening. So a novice user is probably going to think their save hasn't worked and click the Save Button again, and again....
It would be useful to have a spinner, or preferably a progress bar of some sort, either in the file tree or as a whole-of-app overlay to show that a save is in progress.