[lib/native] Extract link parsing utils to lib

Summary:
This is going to be done in preparation to unify all deep link handling logic on native since we now have two deep link cases to handle. The end goal is to have just one handler to reduce
boilerplate and similar behavior across different handlers.

This will also make it easy to handle a new link down the line. In this diff, I've just moved the parsing-specific functions to lib/facts/links.js alongside the methods that construct the links.

This is not part of a monthly goal, just a follow-up task.

Part of ENG-4810

Test Plan: Ran flow to make sure the types were still ok, ran the app to make sure the imports were correct, and made sure invite links and QR code links were still working.

Reviewers: tomek, atul, ginsu

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D9026