Transform a consumer into a sequence of messages

[Baptouuuu]

For the rebuild of Witness, where the mailbox is essentially a sequence of messages, it may be interesting to add a transformation to the Client to consume a queue as a Sequence.

The API may look like $client->consume('queue')->toSequence().

The drawback of this approach is that in case of an error it can only throw exceptions.

For now this is just an idea, more work needs to happen on Witness before trying to implement this issue.