fix(esm): create package.json with module type, add import extensions…

[LouisStairwage]

Do not accept the PR this way the code is error prone because of regex use for parsing imports in JS files.

Hi, this PR will be the first of serie for fixing ESM builds in antd galaxy libraries (antd-icons, rc-*, antd), father is used everywhere in these projects and could help fixing some issues describe by my coworker here : issue on rc-util, issue on antd

It adds :

• Creation of a package.json file with "type": "module" or "commonjs" in it at build's root.
• ⚠️ A code block that parses relative esm imports in files with regexs, resolves final relative modules paths (because ESM spec requires full relative path imports), it should certainly not be done that way, parsing files by implementing a transformer plugin or directly parsing ast and transforming it yourselves.

[LouisStairwage]

Just as an edit, I just saw fatherBabelPluginImportLib2Es, these adjustments could be implemented in plugins using babel too and implemented in antd / rc projects. Any opinions on this ?

[jer-sen]

@sorrycc why did you close this PR ?