otelmongo: replace ConnectionID parsing wth server host & port once mongo-driver exposes it

[prestonvasquez]

Context

otelmongo's peerInfo derives network.peer.address and network.peer.port by running net.SplitHostPort on mongo-driver command event's ConnectionID. In V2, that value is formatted as host:port[-N] so the instrumentation has to reverse-engineer the driver's internal connectionID format.

Definition of Done

When mongo-go-driver releases GODRIVER-4058, we should populate network.peer.address and network.peer.port directly from the monitoring event.