Idea for RFC to generalize the onRun action property in <StepActions> to be either a single <Action> or be a list of <Action>s

[edwards-aws]

This is a continued discussion from #77

From the original discussion

Generalize the onRun action property in <StepActions> to be either a single <Action> as defined currently, or be a list of <Action>s. While in #68, we found an alternative way, by allowing a list of sequential actions in the onRun of a task, each command can get separate timeout and cancelation behavior.

While writing RFC: FEATURE_BUNDLE_1: Collection of Small Improvements it was determined that the ambiguity and scope of this change warrants its own RFC.

Some things to consider

1. Failure Behavior: What should happen when any of the actions in the
   sequence fails? Should the entire step fail immediately, or should subsequent
   actions still execute? Should this behavior be configurable, and if so, how?

2. Semantic Clarity: Is this feature merely syntactic sugar to section off
   portions of a script, or does it represent a fundamental change in how steps
   are structured? The distinction matters for implementation and user expectations.

3. Individual Action Configuration: Should each action in the sequence have
   its own timeout and cancelation behavior?

4. Execution Semantics: Should actions execute strictly sequentially, or
   should there be options for parallel execution?