Feature Request: Official Lib for `re`/`regex`

[一颗布洛芬]

Refer: #241

I checked re implement of https://github.com/qri-io/starlib/tree/master/re which is a tough draft.

Regex is very common and useful. Any ideas to support it as official lib?

[magnetde]

Maybe this will help you if you need another regex module for Starlark: https://github.com/magnetde/starlark-re

I created this Starlark module with the primary goal of having a regex module almost completely compatible with the Python "re" module.