Pipeline updates

[c-ryan-k]

• Adds weekly scheduled semantic analysis pipeline definition
• Converts existing release pipeline to ADO yaml and adds the following features / steps:
  • Updates Node version from 12 to 14 to fix build error
  • Runs on hosted agent pools
  • Adds SBOM manifest generation
  • Determines commit tag from package.json
  • Publishes artifacts to ADO pipeline
  • Adds runtime parameters to pipeline for various build switches (RC / release builds, github / marketplace publish switches)

Also adds a utility script (used in some of our other VSCode extension pipelines) to modify package.json for release candidate builds.