Change Details

Part of [ENG-6145](https://linear.app/comm/issue/ENG-9644/backup-service-backup-client-work-for-a-minimal-version-of-backup). Tracked in [ENG-9650](https://linear.app/comm/issue/ENG-9650/implement-integration-tests-to-new-backup-service-client-api). 1. Create mod for utils, similarly to e.g. `blob_utils` 2. Reduces code duplication 3. Move code to a place so it can be used in more places (later in the stack I'll add a lot more backup integration tests) Depends on D13809

Part of [ENG-6145](https://linear.app/comm/issue/ENG-9644/backup-service-backup-client-work-for-a-minimal-version-of-backup). Tracked in [ENG-9650](https://linear.app/comm/issue/ENG-9650/implement-integration-tests-to-new-backup-service-client-api). 1. Create mod for utils, similarly to e.g. `blob_utils` 2. Reduces code duplication and cleanup 3. Move code to a place so it can be used in more places (later in the stack I'll add a lot more backup integration tests) Depends on D13809

Part of [ENG-6145](https://linear.app/comm/issue/ENG-9644/backup-service-backup-client-work-for-a-minimal-version-of-backup). Tracked in [ENG-9650](https://linear.app/comm/issue/ENG-9650/implement-integration-tests-to-new-backup-service-client-api). 1. Create mod for utils, similarly to e.g. `blob_utils` 2. Reduces code duplication and cleanup 3. Move code to a place so it can be used in more places (later in the stack I'll add a lot more backup integration tests) Depends on D13809