Add project home check to validation window #467
Description
Let's add a new validation rule to check if project has the project_home variable set. If so, this breaks things on other devices.
Let's also have a fix me button that will automatically fix the issue when user clicks on it in the validations window. The fix is to clear it out (bear the same value as in a new project).
Original text:
If a user sets QGIS project home outside of current project folder, it becomes an absolute path and messes up the project when synced.
We should probably check the project home setting and clear it if it points to an external folder.