The contents of the IAM credential report should be a standalone resource rather than part of the IAM User resource

Also the following fields have been added to the Credential Report that we should be grabbing:

access_key_1_last_used_date
access_key_1_last_used_region
access_key_1_last_used_service
access_key_2_last_used_date
access_key_2_last_used_region
access_key_2_last_used_service
password_last_used