Finalized HTTP Command message defer

Message deferring will now always work.

CommandHTTP update

Added ability to defer messages when they are sent to NSQ via HTTP.

Hotfix

Fixed Queue to accept both NSQClient\Message\Message and NSQClient\Message\Bag again.

PHP 7.4 update

Forked from moolex/nsqclient-php NSQClient and updated to use PHP 7.4 and, more importantly, updated to support latest react/event-loop.