Adds key to TG name

[JaredDarling]

The purpose of this is to address an issue encountered when trying to configure an ELB for Blue/Green deployment configuration.

AWS CodeDeploy developer documentation describes this scenario in more detail. https://docs.aws.amazon.com/AmazonECS/latest/developerguide/deployment-type-bluegreen.html

When attempting to configure a Fargate application using cn-terraform/ecs-fargate/aws module, the target_groups are configured as:

  lb_http_ports       = {
    blue = {
      listener_port     = local.production_port
      target_group_port = local.target_port
    },
    green = {
      listener_port     = local.target_port
      target_group_port = local.target_port
    }
  }

With the current naming scheme, it results in the terraform-aws-ecs-alb module throwing an error attempting to create two TGs with the same name. The only fix is to make the target_group names unique. The name property was being extract in the for loop, but was never used. This change simply uses the property value that was already available and it gives implementors more control over TG names.

[JaredDarling]

Will need an assist w/ merging. Branch rules limit merging to main to only 'authorized' users.