[identity] Add function to remove device from list

Summary:
Similiar to D10220 but for removing a device from the list.

Depends on D10304

Test Plan:
Repeated test plan from D10220 then called this function and verified a new list was generated without the device.
Called the function twice - got DeviceNotFound error during second call, as expected.
Calling Logout RPC has the same effect.

Reviewers: varun, michal

Reviewed By: varun

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D10397