Add package validator in typescript

[skh]

To be able to use the package validation from this repository in EPM in Kibana, we need to publish an npm package to the @elastic namespace on https://www.npmjs.com/ . From there, we can import the package in Kibana like any other npm package.

Publishing to npmjs.com can be done manually whenever we have a release.

• Create a subdirectory code/typescript
• create a standard npm package there
• implement a stub validator
• add tests & integrate into CI of this repository
• document how to use a local checkout of the validator in a local checkout of kibana for development
• publish to npm
• automate publishing to npm?
• implement the real validator

[skh]

cc @jfsiii

Feel free to adjust the initial description, this is mostly a brain dump of mine.

[jen-huang]

Closing as won't fix: we haven't come across the need for this in the past few years, so the effort of doing this work won't provide much benefits.