[keyserver/lib/native] flip the switch for farcaster channel tagging

Summary:
This diff flips the switch for the farcater channel tagging UI. Please note that this UI is still gated if you don't have an fid yet.

Depends on D12500

Test Plan: Confirmed that with an fid an admin could enter the farcater channel tagging ui

Reviewers: ashoat, kamil, will

Reviewed By: ashoat

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D12503