[7/n] Native Typeahead - Introduce tooltip component

Summary: This is component that takes currently typed text, regex matches, suggested users and creates overlay with clickable buttons that insert usernames into text input.

Test Plan:
Checked if app builds.
Will be tested in next diff when it's displayed.

Reviewers: tomek, inka, ginsu, kamil, michal, ashoat

Reviewed By: tomek, ashoat

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

Differential Revision: https://phab.comm.dev/D6369