Allow for devices to register as a keyserver
Summary:
Previously, all devices were being registered as
a "client" regardless.
https://linear.app/comm/issue/ENG-4521
Depends on D8627
Test Plan:
Integration tests
Register keyserver locally, and ensure it displays as a "keyserver" deviceType.
Reviewers: bartek, varun
Reviewed By: bartek
Subscribers: ashoat, tomek
Differential Revision: https://phab.comm.dev/D8642