ENH: Add PerformanceBenchmarking remote module CID blobs (9 files, 20.85 MiB)

Stages the 9 binary blobs referenced by .md5 key files in the ITK
PerformanceBenchmarking remote module so ExternalData can resolve
them against ITKTestingData/CID/ after the module migrates from .md5
to .cid keys.

All 9 blobs were recovered locally: 6 from
$ExternalData_OBJECT_STORES/SHA512/ and 3 from the existing
ITKTestingData/MD5/ tree. Each blob was verified by re-hashing to its
MD5 key and by computing its CIDv1-raw (sha2-256) identifier from
file contents. No network fetches were required.

A companion PR is needed on the PerformanceBenchmarking module itself
to convert the .md5 key files to .cid (paralleling ITKMontage commit
4e86c70).

Assisted-by: Claude Code — md5->cid ingest + verification pipeline

Author: hjmjohnson