Support exposing dashboard OTLP endpoint via a dev tunnel

There are scenarios where it would be useful to expose the dashboard OTLP endpoint via a dev tunnel so that other resources can send OTel data to an address other than localhost, e.g. mobile emulators running MAUI apps.

General idea is that it should be possible to configure a resource to send its OTel data to a dev tunnel endpoint rather than the dashboard's localhost address. This would likely be done in conjunction with #11377.