Merge branch 'refactor/calendar-overview' of edugit.org:AlekSIS/official/AlekSIS-Core into refactor/calendar-overview

Merge remote-tracking branch 'origin/894-dialogobjectform-does-not-clear-fields-on-successful-creation' into refactor/calendar-overview

Merge branch '895-group-query-fails-in-some-cases-probably-when-queried-by-a-member-owner' into 'master'

Resolve "Group query fails in some cases (probably when queried by a member/owner)"

Closes #895

See merge request !1300

Translations update from Weblate

See merge request !1301

Currently translated at 100.0% (219 of 219 strings)

Translation: AlekSIS/AlekSIS-Core-Frontend
Translate-URL: https://translate.edugit.org/projects/aleksis/aleksis-core-frontend/de/

This makes using the form more then once a much better experience.

Manage holidays

See merge request !1261

Translations update from Weblate

See merge request !1279

Currently translated at 100.0% (640 of 640 strings)

Translation: AlekSIS/AlekSIS-Core
Translate-URL: https://translate.edugit.org/projects/aleksis/aleksis-core/de/

Translations update from Weblate

See merge request !1297

Currently translated at 100.0% (212 of 212 strings)

Translation: AlekSIS/AlekSIS-Core-Frontend
Translate-URL: https://translate.edugit.org/projects/aleksis/aleksis-core-frontend/de/

Update translation files

See merge request !1296

[Docs] Add missing package

See merge request !1295