Mediator: Reconcile live-mode-postgres branch with main

We currently deploy our [Credo Mediator ](https://github.com/openwallet-foundation/didcomm-mediator-credo) from a branch
https://github.com/openwallet-foundation/didcomm-mediator-credo/tree/live-mode-postgres
on the OWF Credo Mediator repo.

It's diverged from main in ways.
We should try and get our branch in sync with main but there's a lot of potential issues with the credo upgrade.
Or if this is a permanent state, make other arrangements (fork?)

Start by comparing the live-mode-postgres branch with main in the linked OWF Credo Mediator repository and reviewing the differences related to the Credo upgrade. Determine whether the branch can be reconciled or needs a permanent alternative such as a fork; done means the deployment branch is synchronized or the replacement arrangement is documented.

Written by the indexing model from the issue text.