UI: Reports when saving a file.
- T71493 No info in status bar when saving file from the menu
- https://devtalk.blender.org/t/locked-files-problems/8887
Now the behaviors are consistent for blend, image and text files:
- If the file is not writable, will report it.
- If the file is new (without a path), save as will be used.
- If the file was deleted, will try to recreate it.