Bugfix: Fix libre-graph status codes

creating group: https://owncloud.dev/libre-graph-api/#/groups/CreateGroup
changed: 200 -> 201

creating users:
https://owncloud.dev/libre-graph-api/#/users/CreateUser
changed: 200 -> 201

export GDPR:
https://owncloud.dev/libre-graph-api/#/user/ExportPersonalData
changed: 201 -> 202

https://github.com/owncloud/ocis/issues/7678
https://github.com/owncloud/ocis/pull/7705
