[web] [fix] update menu button size, correct addition bottom padding

Summary:
fix menu button size, including fixing the additional 2-3px bottom padding from the button element

Confirming vertical-align is the functionality that we want:

Test Plan: check the figma file, additionally, if you want to render the component locally, set the false conditions in thread-menu menu items to true

Reviewers: atul, ashoat, palys-swm

Reviewed By: ashoat, palys-swm

Subscribers: def-au1t, marcinwasowicz, ashoat, palys-swm, Adrian, karol-bisztyga

Differential Revision: https://phabricator.ashoat.com/D3331