feat(user_saml_shibboleth): Provide group information

[blizzz]

For nextcloud/user_saml#662

• More testing, ensuring that groups data is indeed provided with the SAML Response at login
• add integration tests
• fix quota information not provided
• add changes to 7.3 version?
• drop first three commits
• Publishing docker images for dirsrv and shibboleth-idp (post merge)

So far, inside the container worked as desired:

/start.sh
# wait until services are there
ldapsearch -LLL -H ldap:/// -x -D "cn=Directory Manager" -w password -b dc=idptestbed "memberof=cn=Students,ou=Groups,dc=idptestbed"
# Shows both student users
ldapsearch -LLL -H ldap:/// -x -D "cn=Directory Manager" -w password -b dc=idptestbed "(&(objectclass=groupOfNames)(member=uid=student1,ou=People*))"  cn
# shows Students and Astrophysics group, where student1 is member of

[blizzz]

already helped to get aware of a naming and transition scenario nextcloud/user_saml#662 (comment)

[blizzz]

• fix quota information not provided

nextcloud/user_saml#662 extends integration tests, but that one providing the quota keeps failing, even after latest changes today. Since it works with manual testing via Keycloak, it appears this shib configuration does not provide the quota value and needs further investigation.

[blizzz]

@juliushaertl done here. Do you want to re-review? Latest run uver at at user_saml is failing, but not anymore due to the images, it now appears to be a logic issue. Quota and Group info are all applied and delivered.

[juliushaertl]

Without knowing much about configuring the Sibboleth IdP itself config changes and ldif look sane from reading through it 👍