Support splitting out composite action steps [GA]

### Value Prop

Customers appreciate the way composite actions enable them to easily take multiple steps and repeat them easily in jobs. However, they also wish to split out the steps within the job rather than keeping it within the composite action. This increases readability and makes it easy for users to analyze individual steps.

### Expected Outcome
Enable composite actions to split out their steps within a job, rather than being treated as a single composite entity.