Compare fog vs storage-cli benchmarks

[kathap]

• A short explanation of the proposed change:
  This change extends the blobstore benchmark to explicitly instantiate and use separate blobstore clients per backend by passing a blobstore_type override (fog or storage-cli) into DependencyLocator.
  The benchmark now runs side-by-side measurements for packages, buildpacks, and droplets using both blobstore implementations within the same execution, ensuring each upload, download, and delete operation is performed against the intended backend.

• An explanation of the use cases your change solves
  Accurate performance comparison, validation of experimental storage-cli support, regression detection

• I have reviewed the contributing guide

• I have viewed, signed, and submitted the Contributor License Agreement

• I have made this pull request to the main branch

• I have run all the unit tests using bundle exec rake

• I have run CF Acceptance Tests