Seperate metrics from the debug server

[dragonchaser]

At the moment we server the /metrics , /healthz and /readyz through the debug server in each service. This should be seperated since those endpoints should be reachable all the time, without enabling the debug server.

Possible implementations

• Add an additional server for metrics and status endpoints
• Implement those endpoints into the regular http server of each server.

It would also make sense to add the /config endpoint there (open for discussion).

Follow-up to: #8783

[tbsbdr]

wont fix