Swap FKs dependency_proxy_blob_states to dependency_proxy_blobs and namespaces for LFK

Summary

Verification state tables are cell-local. None of their rows should be copied to destination cells by Org Data Migration. But many of them still have foreign keys to non-cell-local tables. The tables with foreign key references are: dependency_proxy_blobs and namespaces. We are going to replace the foreign keys with "loose foreign keys".

Foreign keys to swap:

• dependency_proxy_blob_states.dependency_proxy_blob_id → dependency_proxy_blobs.id
• dependency_proxy_blob_states.group_id → namespaces.id

Implementation

Follow the loose foreign keys documentation and use !185323 (merged) as an example.