Missing support for the aws:loop automation action

There is no step class for the [aws:loop](https://docs.aws.amazon.com/systems-manager/latest/userguide/automation-action-loop.html) action.

Is there a technical reason for this? I thought that maybe recursion would be an issue in supporting the action, but the AWS console doesn't allow you to create nested loops.

If it can't be implemented for whatever reason, then are there any escape hatches that would allow me to inline the raw step JSON? I tried using StringStep, but that appears to deconstruct the JSON into a loop step object... which doesn't exist. Is there any other way?

Start by reading the AWS Systems Manager documentation for the aws:loop automation action and tracing the existing step classes, including StringStep. Determine whether a loop step can be represented safely, or whether raw step JSON can be preserved; done means either documented loop support or a verified escape hatch for this action.

Written by the indexing model from the issue text.