chore: logging received message info via onValidated observer

[gabrielmer]

Description

Logging information related to received messages by using one of the new onValidated nim-libp2p observers. This is improves our current approach of logging via the traceHandler, which does not provide information on who sent the message a node received.

Changes

• setting onValidated logger observer
• removed message received logging from traceHandler
• added message received log when a message is sent via REST, as per DST request
• renamed initRelayMetricObserver to initRelayObservers

Notice that a "message received" log were added to the REST endpoints that publish messages. This is per DST's request, so they can easily tag the node that published a message to the network as a node that has seen the message.

CC @AlbertoSoutullo

Example

[github-actions]

You can find the image built from this PR at

quay.io/wakuorg/nwaku-pr:2973

Built from c3828f3

[AlbertoSoutullo]

To add a bit of context regarding added message received log when a message is sent via REST:
In order to check message reliability via logging, the problem we were facing when messages were being injected in the network via REST is that all nodes were logging the received message but the node that started the publishing. So we wanted a way to make sure that at least this node also "received" this message but from a different way, so we could make sure this happened, instead of assuming it, if it makes sense.

[Ivansete-status]

Gorgeous one! Thanks so much for it! 💯

[SionoiS]

LGTM thanks!