[native] helper for pake login on client side

Summary:
This helper function takes the PAKE login response from the server and completes the final step on the client side. It handles the error mapping and checking if the ClientLogin object is present

Depends on D4800

Test Plan: Tested in next diff in stack

Reviewers: tomek, karol

Reviewed By: tomek

Subscribers: ashoat, adrian, atul, abosh

Differential Revision: https://phab.comm.dev/D4801