Prepare client services for instrumentation

[sechmann]

The device-{helper,agent,systray} services lack instrumentation. The only way we can debug issues related to these is to ask developers to send us logs.

Consider instrumenting these services using OTEL

https://grafana.com/docs/opentelemetry/instrumentation/go/manual-instrumentation/
https://doc.nais.io/observability/frontend/

We will also have to keep privacy in mind while adding this.

This task should be limited to getting the reporting part working, and a few example measurements. Full instrumentation will have to be achieved over time.

[mortenlj]

I think we would want to collect naisdevice telemetry from all tenants, and if so, we can't use the telemetry.nav.no endpoint that exists for NAV.
We would need to set up a separate endpoint for naisdevice clients.
We should probably also make it possible to pass the endpoint to the clients, so that we can change the endpoint without releasing a new version, and also to make it possible to use a development endpoint when we are developing naisdevice.