CNG: Support decomposed database in wait-for-deps scripts

Summary

As part of gitlab-org&6271 (closed) will have the possibility to contain multiple stanza for different databases. As a result, we'll need to to check all of them are reachable and up to date.

Post #2808 (closed), we have support for production or production.main. We do not have support for production.ci

Current behavior

Watching only for production or production.main keys.

Expected behavior

All keys under production are walked & checked for status.