[dev]: workflow improvements

[Shaun Hamilton]

• Separate testing content from package
  • Currently, testing involves installing "@freecodecamp/freecodecamp-os":"." which needs to be removed before publishing
  • Currently, bugs slip through with the pathing, because the tooling does not reference itself in node_modules
• Build client as part of publish
• #448
• Entirely reference modules with @freecodecamp/freecodecamp-os - not ROOT/node_modules/...