Use .workflow-patcher.yml to update a workflow

[ArBridgeman]

Summary

In #691, we defined a customization YAML, let's define how this works with a workflow template to do the steps it describes.

• Switch to better custom exceptions
• Perform steps
  • remove jobs
  • REPLACE
  • INSERT_AFTER
• Test that this works as intended
• Expose to tbx and/or nox endpoints
• Modify documentation to detail how to use
• workflow:check
• check existing workflows to see if any deprecated & warn user + watermark at top