[web] Prevent web Menu from dismissing itself on open

Summary:
Some change in React 18 is making document.addEventListener('click', closeMenuCallback) execute faster than before, and somehow it's able to catch the click that created it. Not sure how this is happening, but the fix is easy: stop the propagation of the click event once we handle it.

This solves https://linear.app/comm/issue/ENG-2534/cant-press-three-dots-button-in-messagelist-on-web

Test Plan: Make sure I can open the "three dots" menu in the MessageList on web

Reviewers: atul, ginsu, tomek, jon

Reviewed By: atul, ginsu

Differential Revision: https://phab.comm.dev/D6016