Resolve "Change default Apollo network policy to cache-and-network"

See merge request !1194

# Conflicts:
#   CHANGELOG.rst

Merge branch '809-sw-delivers-offline-fallback-page-when-status-code-is-not-between-200-299-response-ok' into 'release-3.0'

Resolve "SW delivers offline fallback page when status code is not between 200-299 (response.ok)"

See merge request !1193

Translations update from Weblate

See merge request !1187

Currently translated at 100.0% (628 of 628 strings)

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

Update translation files

See merge request !1186

Activate WebAuthn and redesign 2FA profile page

See merge request !1099

Merge branch '785-verify-maintenance-mode-with-graphql-reimplement-maintenance-mode-handling' into 'master'

Resolve "Verify maintenance mode with GraphQL / reimplement maintenance mode handling"

Closes #785

See merge request !1154

Translations update from Weblate

See merge request !1175