[8.0] feat (VOMS2IAM): add options to sync from IAM

[chaen]

Addresses part of https://github.com/DIRACGrid/DIRAC/issues/7416

This does not yet work, because there are still too many bugs in the voms-importer https://github.com/indigo-iam/voms-importer/

Wht this PR does is to add 2 options to the VOMS2CSAgent`:

• CompareWithIAM: when set to true, we will dump the users from IAM, and print a comparison with what VOMS sees
• UseIAM: not query voms-admin anymore, but the IAM endpoint

BEGINRELEASENOTES

• Configuration NEW: VOMS2CSAgent can query IAM

ENDRELEASENOTES