feat: emit an event in EventBus upon dial error

[adklempner]

Description

Upon error dialing in PeerConnectionStrategy.dialPeer or WakuNode.connect, emit a DialError event. This allows consumers of go-waku to subscribe to a channel which outputs the dial errors as they occur.

Changes

• Create DialError interface in utils
• Add an event emitter for DialError events to PeerConnectionStrategy (created in Start(), closed in Stop())
• Add a function HandleDialError to PeerConnectionStrategy that:
  • runs existing logic on dial failure (add backoff, add to connection failures in waku peer store)
  • emit a DialError event using the ID of the peer and the returned error message from c.host.Connect(ctx, pi)
• use above function in PeerConnectionStrategy.dialPeer and WakuNode.connect when an error is returned by host.Connect

Tests

[richard-ramos]

LGTM!