IAM Policy Attachment - Lookups for built-in policies

[zachreborn]

Describe the feature

Add the ability to lookup a built-in policy based on the name of the policy and automatically fetch the ARN to add to the IAM user or group.

Examples

module "example_user_policy" {
  source = "github.com/zachreborn/terraform-modules//modules/aws/iam/user_policy_attachment"

  policy_name = "AWSApplicationDiscoveryAgentAccess"
  user       = module.migration_evaluator_collector.user_name
}