[web] Remove extraneous CSS selectors

Summary:
Context: https://phab.comm.dev/D10528#inline-64165

Quick 2 second diff. Ran IDE "Unused CSS selector" inspector to detect obvious unused CSS selectors. There were additional ones detected, I just selected the ones where there was no string match in codebase to be safe.

Test Plan: NA, searched codebase for the selector names and found no occurences.

Reviewers: ginsu

Reviewed By: ginsu

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D10547