[native] Exclude primaryIdentityPublicKey from siwe_auth request

Summary: We added primaryIdentityPublicKey to logInExtraInfo to make it easily accessible in the native RegisterPanel and LogInPanel. However, it led us to include extraneous primaryIdentityPublicKey in siwe_auth request which broke the siwe_auth input validation.

Test Plan:
Make sure that SIWE works on native

Reviewers: ashoat

Reviewed By: ashoat

Subscribers: tomek

Differential Revision: https://phab.comm.dev/D6793