NocoDB: Cross-Workspace Integration Use in Connection Test

Summary

A user in one workspace could exercise another workspace's integration through the
testConnection endpoint by supplying its ID, because the integration was fetched in
a bypass scope and the caller's permission check matched any base in any workspace.

Details

The connection-test endpoint fetched the integration in RootScopes.BYPASS scope and
checked only that the integration was non-private and that the caller held an
owner/creator role on any base in any workspace. The permission lookup is now scoped
to the integration's workspace by joining on fk_workspace_id, and the controller
rejects requests where the integration's workspace differs from the request's workspace.

Impact

Cross-tenant access to integration configuration through the connection-test endpoint,
including the ability to drive the resolved database with the other workspace's
credentials. Authentication with creator-or-owner role on any base in any workspace
was sufficient.

Credit

This issue was reported by @DongyangLyu.