Determine basic cluster state via ping

[mbfm]

To be able to determine when a cluster might be ready - not necessarily that it is fully healthy - we could do a basic ping on the peers and accumulate the results in CARL.

Tasks:

• [x] Instruct EDGAR to ping via PeerConfiguration-Parameter (to obtain a ParameterId).
  • [x] CARL sends Parameter
  • [x] EDGAR uses Parameter
• [x] CARL is able to receive messages
• [x] EDGAR is able to send messages
• [ ] Define a model with which the information can be reported to CARL.
• [ ] EDGAR notifies CARL when Ping succeeded or failed

For this to be more useful, we might want to also fix #324.