Resolve "Fehlermeldung TypeError: this.initialNavigation is null auf Seiten, die sich nicht in die Navigation einhängen"

Closes #2435

Merge request studip/studip!1627

Closes #2376

Merge request studip/studip!1676

Closes #2037, #1759, and #2097

Merge request studip/studip!1326

Thomas Hackl authored 2 years ago and David Siegfried committed 2 years ago

Closes #32

Merge request studip/studip!65