* feat: add CSP and other security related headers in the oCIS proxy service
* fix: consolidate security related headers - drop middleware.Secure
* fix: use github.com/DeepDiver1975/secure
* fix: acceptance tests
* feat: support env var replacements in csp.yaml
* enhancement: add graph beta listPermissions endpoint
besides the new api endpoint it includes several utilities to simplify the graph api development.
* resolve drive and item id from the request path
* generic pointer and value utilities
* space root detection
* update GetDriveAndItemIDParam signature to return a error
* move errorcode package
* enhancement: add generic error code handling
* fix: rebase
As keycloak already supports everything needed for the required
invitation flow, it's ideal to use as the first backend to create users
and to send them invitation mails.
This PR implements that as the first and (for now) only backend.
