MULE-8018: Merge http connector code cleanup

We use the lifecycle interfaces for registry lifecycle yes, but I'm not sure why that means they can't be re-used for other objects that share the same behaviuor (i.e. they can be started) as there is nothing that ties Startable to registry or anything else

Also, it seems kinda strange that the implementation of HttpListener *does* implement existing lifecycle interfaces, yet the interface defines it's own lifecycle methods.