Motivation

For some specific reason (related to us still using sqlx migrations), I happen to need an sqlx connection from the pool which I don't seem to be able to get. It would be nice to have a feature that allows us to get it.

Proposed Solutions

1. Add a crate feature (i-hop-in-breaking-changes or something like that)
2. Add a method under this feature flag to get the raw sqlx connection from the database pool