[services] Tests - Backup - Move compare backups to backup utils

Summary:
Depends on D4634

Excluding the functionality of comparing the backups from the backup integration test into the backup utils so it can also be used in the backup performance tests.

Test Plan:

cd services
yarn run-performance-tests backup 1

Reviewers: tomek, varun

Reviewed By: tomek

Subscribers: ashoat, tomek, adrian, atul, abosh

Differential Revision: https://phab.comm.dev/D4635