enhancement(graph): cs3PermissionsToLibreGraph can also return v1beta1 format

This reworks the cs3PermissionsToLibreGraph() so that it is able to return
the libreGraph.Permissions in the legacy and the new v1beta1 format. The main
differences between both are that v1beta1 returns the identities in the
'grantedToV2' property and the 'roles' are returned as IDs instead of the
legacy role names.
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f