feat: Ability to configure deployment environments (including their secrets/variables)

[actuarysailor]

Description

Updated the action to enable the configuration of:

• Deployment Environments #218, including:
  • Deployment Protection Policies
  • Variables
  • Secrets

Motivation and Context

I manage several hundred repositories at work, and we use templates to ensure that everyone has the correct CI/CD pipelines for various project types varying by platform, programming language, and teams responsible for them. While this action does not fully automate everything such that all repositories require no manual configurations, it does streamline the configuration process for new repositories, such that:

• Baseline permissions for contributors get automatically set
• Baseline configurations for common settings get automatically set

While new repositories still need their settings.yml file updated for any customizations specific to a new repository, this allows even non-admins to propose those updates via a pull request. Secret values may still need a manual configuration because it is not guaranteed that:

• the worker running this action would have the appropriate values stored in an environment variable
• hard-coding secret values into the settings.yml file directly defeats the purpose of having an encrypted repo secret

How Has This Been Tested?

• [x] I have updated at least one of the examples/* to demonstrate and validate my change(s)
• [x] I have tested and validated these changes using one or more of the provided examples/* projects

[andrewthetechie]

Closing these per discussion with @actuarysailor in another PR.