[Identity] Show consumed capacity when running query

Summary:
Follow up from https://phab.comm.dev/D8722#inline-56482

Depends on D8817

Test Plan:
Start identity service, tunnelbroker

cd services/commtest
cargo test --test identity_keyserver_tests

Reviewers: bartek, varun

Reviewed By: bartek

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D8878