Manage EC2 instance via AWS Systems Manager

[mtrivedi50]

Is your feature request related to a problem? Please describe.
Certain organizations prefer to use AWS Systems Manager to provision, modify, and execute commands on EC2 instances. Alto currently does not support this.

Describe the solution you'd like
Add compatibility with the AWS Systems Manager. Tactically, this could involve adding a protocol key to the infra portion of the configuration file that defaults to ssh but can be set to ssm. When a user specifies that they want to use the ssm protocol, Alto should build all the requisite resources (e.g., instance profile) for them.

Describe alternatives you've considered
N/A

Additional context
N/A