Move tbx workflow endpoints to nox sessions

[ArBridgeman]

Summary

As there will be updates to the workflow endpoints for #425 , it would be beneficial if we moved and deprecated/deleted some of these endpoints:

• list -> deprecate/delete
• show -> deprecate/delete
• install -> deprecate/delete
• diff -> deprecate/move
• update -> deprecate/move

to be nox sessions instead.

To Do

• Deprecate / delete list, show, install endpoints
• Create a class (i.e. Enum) for all the workflow templates given by the PTB to be used for the nox sessions workflows:x
  • Create a test in the PTB to verify that this tuple matches the tuple of files in toolbox/templates/github/workflows/
  • Create a property for this class called custom which lists whatever workflows for the project are not listed in the class.
• Deprecate & move diff to nox session workflows:check
  • when there are differences, this should print out all workflow differences & exit with a 1
  • when there are NO differences, this should exit with a 0
• Deprecate & move update to nox session workflows:update
  • drop the confirm check & instead add/overwrite the file
• Update the user & developer guide
• Add/modify tests
• Create a follow-up issue (to be done later / at the end) to remove deprecated endpoints. This is not needed if they were deleted & we're releasing a major version.