[native] introduce barebones TagFarcasterChannelNavigator + TagFarcasterChannel screen

Summary:
This diff introduces the barebones navigational logic needed for introducing TagFarcasterChannelNavigator and the TagFarcasterChannel screen. Subsquent diffs will handle extending both of these to match the UI/UX with the rest of the app

Linear tasks: https://linear.app/comm/issue/ENG-7538/introduce-tag-farcaster-channel-option-in-the-community-actions-menu + https://linear.app/comm/issue/ENG-7539/introduce-tagfarcasterchannelmodal-screen + https://linear.app/comm/issue/ENG-7540/introduce-navigational-logic-for-tagfarcasterchannelmodal

Test Plan: flow + confirmed that I could navigate to TagFarcasterChannel from community action buttons

Reviewers: atul, inka

Reviewed By: atul

Subscribers: will, ashoat, tomek

Differential Revision: https://phab.comm.dev/D11662