[lib][web][native] Use uuid for next local id

Summary:
issues: ENG-6074 and ENG-6075
We want to start using uuid in place of manually calculated local id.

Test Plan: Tested (on native) that it is possible to create events, send text messages, send multimedia, react

Reviewers: michal, ginsu

Reviewed By: michal

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D11552