[ENH] Adding SSM to EC2 instance as alternative way to connect to instances

Currently by default there is SG created with IP whitelist. This approach is great for simple setup and when there is no need to share access with others. However, for more complicated cases, SSM is a great way to connect to EC2 instances. This can be easily added by adding AWS Managed policy to instance roles.

If this feature will be approved I can create PR with changes.