[native] add linkFarcasterAccount to commRustModule

Summary:
calls the rust client method introduced in previous diff

Depends on D11407

Test Plan: in the next diff I call this method from JS and update an existing user to include a FarcasterID. confirmed the result in DDB.

Reviewers: bartek

Reviewed By: bartek

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D11408