ec2 to ec2_instances module migration

[piwi3910]

in this pull, I'm laying the groundwork to support later Ansible version where the ec2 module will be deprecated in favor of ec2_instances Currently, there are a few modules that only recently got merged in ansible 2.10 devel that will allow us to move the metric module to support boto3. This will allow us to enable the new zones like me-south-1 that are currently not supported with boto and they don't accept pull requests for it.