Show optional response event when sending an event

It would be great to show the HTTP response when a CE has been sent when testing microservices that consume and _produce_ Cloud Events as response.

Currently, the response is just ignored. The Golang CE SDK supports a more sophisticated way to send events that also allows the inspection of the response via https://github.com/cloudevents/sdk-go/blob/de2f28370b0d2a0f64f92c0c6139fa4b8a7c3851/v2/protocol/http/protocol.go#L178

Not sure how to get this from the in-cluster sender image to the CLI (except to log to stdout), but for the out-cluster sending from the CLI this should be not too difficult.

Start with the CLI's out-cluster event-sending path and compare it with the CloudEvents Go SDK HTTP protocol implementation linked in the issue. Determine how an optional HTTP response event can be surfaced for CLI sends and how the in-cluster sender image could expose it, then verify that response events are visible without changing the existing send behavior.

Written by the indexing model from the issue text.