Docker: Add OTEL support to server and connector

[gingters]

Add the new-ish default .NET OTEL support to Server and Connector, so that we have spans out of the box.

We can then switch Seq (commercial product) to the Aspire Dashboard as a standalone container (without the need for full aspire) to see Logs, Traces and metrics from all containers on one place, instead of only logs.

This should also allow us to simply consume the exposed rabbit prometheus data as well as monitor the postgresql with OTEL in the aspire dashboard.