Additional validations for input parameters when generating workflows

## Describe the bug

Currently the validation for `BuildActionParameters.actionName` doesn't exist - so you are able to set `actionName = "Hello cool action"` which is then not supported by the Workflow engine


## Expected behavior

During the process of building/creating/synthesizing the workflow there should be an error message at build time to avoid this behaviour.

## Version information

- OS: [e.g. iOS]
- Node.js version: [e.g. 16.14.2]
- Package version: [e.g. 1.0.0]

## Additional context

This is part of our [https://github.com/taimos/projen-pipelines](https://github.com/taimos/projen-pipelines) implementation

Start by locating BuildActionParameters.actionName and the workflow building, creating, or synthesizing entry point. Add validation so unsupported action names produce an error at build time, and verify that valid names continue to work.

Written by the indexing model from the issue text.