Azure provisioner add configurable mail nickname and description

The Azure changelog provisioner, as developed by Unicon, defaults the mail nickname to the group uuid with no way to change it. This should be easily configurable with Jexl expressions.

It also defaults the group description to the Grouper group uuid. For normal membership add/deletes, it can get the Azure id from the o365GroupId attribute. But for group deletions, the PITGroup description was a quick way to retrieve the Azure groupId from the deleted Grouper group without navigating associated PITAttribute queries. This can be refactored to use the PITAttributeAssignValue of the o365GroupId, thus removing the dependence on group description, and freeing it up for arbitrary values.