add readAnyDatabase and stackitAdmin roles for MongoDB users

[PietvanderMeulen]

Description

Adding additional roles for MongoDB users. Taken from the API Docs.

Checklist

• [ ] ~Issue was linked above~
• [x] Code format was applied: make fmt
• [ ] ~Examples were added / adjusted (see e.g. here)~
• [x] Docs are up-to-date: make generate-docs (will be checked by CI)
• [ ] ~Unit tests got implemented or updated~
• [x] Unit tests are passing: make test (will be checked by CI)
• [x] No linter issues: make lint (will be checked by CI)