[web] display farcaster avatar when it's set

Summary:
in D13380 I made it possible to set a farcaster avatar from web. however after refactoring D13101, we won't actually display this avatar from the settings page when it's set without the changes in this diff

Depends on D13381

Test Plan: tested by setting and unsetting all avatar types from settings page on web

Reviewers: ashoat, tomek

Reviewed By: ashoat

Differential Revision: https://phab.comm.dev/D13456