New Workflow - cadquery as first class objects?

I propose a new workflow where CadQuery scripts are first-class objects in FreeCAD files

Branch of my code: https://github.com/risacher/cadquery-freecad-workbench/tree/flow-change

YouTube Demo of what I propose: https://youtu.be/1tKtBxnyLmo

Start with the linked flow-change branch and YouTube demo, then compare the proposed workflow with the current FreeCAD workbench behavior. The issue does not define the file/object behavior or acceptance criteria, so establish those before implementation; done should mean that the agreed first-class CadQuery script workflow works in FreeCAD files.

Written by the indexing model from the issue text.