Add compatibility keyword based on modularity type

[andrew-aladev]

Please review the following gist and issue.

@sindresorhus is the author of 1407 small packages. He tries today to use popularity on npm/yarn for forcing ESM, please review a list of his packages. 90% of these packages provides a new major version with ESM only dist.

For example string-width has been downloaded 302.6 million times and now it is ESM only. It may be funny with amount of downloads about 1K, but now it is not funny and it won't be funny anymore.

He just dropped support of CommonJS modularity type. But any user can still install a new version of package with incompatible modularity type and npm/yarn won't care. Packages provide just small utilities and developer may use them in small scripts outside of main project tests. Developer will think that "this package is too small, it can't provide any harm for me", he will upgrade it and nothing will happen. ERR_REQUIRE_ESM will appear in runtime only (for example in production).

I am sure that npm/yarn should care about modularity type and implement it ASAP, because bomb has already been planted by @sindresorhus.

For example gentoo portage has a special keywords for different architectures: package will be masked for unknown/untested architecture and system won't install such packages without your explicit permission. Ruby bundler has platforms keyword for same purpose. Please add similar keyword for nodejs modularity type.

Please also review an idea to bind modularity type and popularity together. It means that string-width has been downloaded 302.6 million times using CommonJS modularity type. New version of string-width with ESM only modularity type should have 0 popularity.

Thank you.