[MongoDB] CDI named clients

As a follow up of a [discussion still open in Quarkus community](https://github.com/quarkusio/quarkus/pull/11998), we should fix the way we retrieve named mongo clients in mongodb extensions. The PR #1688 should patch the behavior allowing the possibility to use any mongodb client in our routes, but we must follow the work on Quarkus and provide a more reliable solution once that is available.

Start by reading the open Quarkus community discussion and PR #11998, then review PR #1688 and its handling of named MongoDB clients. Confirm the intended upstream solution before changing anything; done means named clients can be retrieved reliably and any MongoDB client can be used in routes without relying on the temporary behavior.

Written by the indexing model from the issue text.