Implement done state for due dates

[juliusknorr]

• Resolves: Mark card as done #534
• Target version: master

Summary

Implements a switch to mark cards with due date as done

TODO

• Action menu to switch the state
• Properly show cards as done with a checkmark
• Make sure this is represented in the dav endpoint
• Add button to the sidebar
• Disable overdue actions and display for done card
• API documentation

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Documentation (manuals or wiki) has been updated or is not required

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[juliusknorr]

Closing for now, to be reopened when continuing, to get the list of open prs a bit more sorted.