build: make test-doc and lint addon docs

- Implements the make test-doc target that build, verify
  and lint docs
- Lint the C++ snippets in addon docs
- When generating addons and running the JS linter,
  use the global node executable if it is not built.
  Therefore one does not have to build node in order to
  run make test-doc.

PR-URL: https://github.com/nodejs/node/pull/16377


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>