Document supportability of tenant_id in all docstring of azure-identity implementation

[lmazuel]

Some credentials instance will support tenant_id, and some won't (like ManagedIdentity). For clarity for users, the docstring needs to explicitly state if the tenant_id will be ignored, or is an effective parameter

All credit for @mccoyp to have raised the issue

[mccoyp]

We should also explicitly state how we do or don't honor claims, and any other arguments specified in the TokenCredential protocol, for future reference