[2/n] Native Typeahead - Adding utility file and native regex

Summary:
Native regex is a little bit different than web one as there are no named captruing groups yet on native.
See: https://linear.app/comm/issue/ENG-2456/rewrite-typeahead-regexes-when-named-capturing-groups-are-released-for#comment-4bb6cf1e

Test Plan: Checked if regex works in online editor.

Reviewers: inka, ginsu, kamil, michal, tomek

Reviewed By: inka, tomek

Subscribers: ashoat, tomek, atul, michal, kamil, ginsu, inka

Differential Revision: https://phab.comm.dev/D6298