feat: reading DC links requires read on the DCs

[olevski]

No description provided.

[olevski]

This change is part of the following stack:

• feat: authz schema changes for data connectors #615
  • feat: data connectors in project creation #617
    • feat: adapt namespace endpoints #638
      • feat: reading DC links requires read on the DCs #642 ◀
        • feat: endpoint for count of inaccessible dc links #650

_{Change managed by git-spice.}