[web] use identity wallet login in siwe-login-form

Summary:
If usingCommServicesAccessToken, call identity service wallet login RPC.

Depends on D11019

Test Plan: Confirmed that action succeeded in redux devtools, inspected payload and confirmed that the access token and user ID matched local DDB

Reviewers: ashoat, inka, tomek

Reviewed By: ashoat

Differential Revision: https://phab.comm.dev/D11020