[identity] Implement attribute conversions for Device row

Summary:
Added From traits to convert DeviceRow from/into AttributeValues. Copied this pattern from other services - it's very handy

Depends on D10213

Test Plan: Tested later in the stack. TODO: Add unit tests

Reviewers: michal, varun

Reviewed By: varun

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D10214