[CommCoreModule] Set readyState to SocketStatus::CLOSED on ClientGetReadReactor::OnDone

Summary: Set readyState to 3: CLOSED once the Get() stream is closed.

Test Plan: Logged readyState and it was as expected

Reviewers: ashoat, palys-swm, def-au1t, varun, karol-bisztyga, jimpo

Reviewed By: ashoat, karol-bisztyga

Subscribers: Adrian, benschac

Differential Revision: https://phabricator.ashoat.com/D3121