[keyserver] Pass calendarQuery to processSuccessfulLogin in siweAuthResponder

Summary:
Context: https://linear.app/comm/issue/ENG-2575/pass-calendarquery-up-from-client-to-siweauthresponder

https://phab.comm.dev/D6060#inline-40815

Should have done this earlier... calendarQuery was already being included in SIWEAuthRequest.

Depends on D6077

Test Plan: Set breakpoints and observed that calendarQuery "made it" to processSuccessfulLogin as expected.

Reviewers: ashoat, tomek

Reviewed By: ashoat

Differential Revision: https://phab.comm.dev/D6078