[web] Replace threadHasPermission with useThreadHasPermission in EditThreadAvatar

Summary:
Followup to D11746 where we're updating client to use hook.

Depends on D11746

Test Plan:
flow/CI/etc.

Thread where I shouldn't have EDIT_THREAD_AVATAR permission doesn't let me change avatar:

Thread where I should have EDIT_THREAD_AVATAR permission DOES let me change avatar:

Reviewers: ginsu, tomek, varun, will

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D11747