[KJots] Save on exit
Summary:
This is follow-up to D29291: [KJots] Provide explicit "Save" action, use standard actions where possible.
When quitting the application, perform a save using the synchronous ItemModifyJob interface.
If the job has failed, show a dialog explaining what can be done to avoid data loss (save it to file using Export menu).
BUG: 296242
Test Plan: Note is now always saved on Ctrl+Q.
Reviewers: dvratil
Reviewed By: dvratil
Subscribers: kde-pim
Tags: KDE PIM
Differential Revision: https://phabricator.kde.org/D29762