Implement *some* package testing for the Supervisor packages

[douglascamata]

This issue is a follow up to the work and conversation at #1209.

We need to add some level of package tests to the deb/rpm opampsupervisor packages that will be produced after the previously mentioned PR is merged.

Considering that the opampsupervisor service requires a Supervisor configuration (with a domain and potentially auth to connect) and a working OpAMP backend, we might not be able to test that the service starts until we figure this one.

Still we can test that the packages are installable and that removing them behave as expected.

[douglascamata]

After open-telemetry/opamp-go#454 is merged I will take a look at whether we could use the example server for this.

[juandemanjon]

@douglascamata I am considering adding a REST API to the server example to automate some UI actions.

Do you anticipate needing any APIs in your test automation for the server example?

[douglascamata]

@juandemanjon hummm, from a testing perspective I think I would need:

• CRUD actions for remote configurations
• Read action for remote configuration statuses. Filter for agent or remote configuration would be helpful.

Aaaand with this I should be able to assert that the Supervisor + Collector that I packaged are working well.