Add new round styles for avatars

- added new round styles for avatars
- cleaned up some old css rules and padding issues
Add sass-variables for round-avatars

- added sass-variables for round-avatars
Truncate long titles and add a tooltip
Change filter name to not misleading title
Add is closed state to WP API model
Use helper method
Test row of closed related WPs is marked correctly
Merge pull request #1672 from netfighter/feature/14432-headlines-cover-edit-buttons
Strike out related WPs that are closed
Is closed propery always exists
Merge pull request #1697 from netfighter/feature/14416-german-translation-is-wrong
Merge pull request #1651 from opf/feature/round-avatars
Merge pull request #1698 from opf/feature/14455_closed_wps_not_stiked_out

[Feature] 14455 closed wps not stiked out
Allow toggling of relation directive's expand status
Fix relation heading style
Apply scope correctly