D.JS serializer

[sergey-shandar]

• to JSON. PR To JSON #102
• to JSON5 ???
• to D.JS
  • D.MJS (ESM)
  • D.CJS (CommonJS)
• dedup option for serializer #99
• refactor to_json.rs: most of it goes to write_js_utilities.rs, what remains in WriteJson is write_json.
• refactor to_djs.rs: WriteDjs should not require WriteJson but should use fn-s from write_js_utilities.rs.
• deduplicate code in to_djs using automatic captures in lambdas.