Implement JSON parse and stringify

A couple of yaks on my way:

  - Add bazel `BUILD` file to frozen
  - Rename some internal mjs functions because they conflicted with
    frozen

PUBLISHED_FROM=fa403fb456b32a9e61af529030c09a12167b8200

Fixed find_json_token() for nested arrays/objects, thanks to Jesse fo…

…r the fix

Added generation API

Respecting utf-8 char length

Fixed code formatting

Fixed code formatting