[web] Remove active drawer item highlight

Summary:
issue: https://linear.app/comm/issue/ENG-3177/change-drawer-highlights
there won't be a highlight for the chat we are currently in

Test Plan: run web app, check that there is no highlight signifying thhe currently selected chat, other that the background behind the selected community in Chat tab

Reviewers: kamil, tomek, michal

Reviewed By: tomek

Subscribers: ashoat, atul

Differential Revision: https://phab.comm.dev/D6977