Can BlHostEventFetcher be merged into host spaces?

[tinchodias]

This fetcher consists on an initialize that creates a WaitfreeQueue, and a couple of simple & short methods to add and to retrieve events from it (enqueueEvent: and fetchedEventsDo:).

There are 3 references:

IMHO, BlHostEventFetcher could be good if there was more complex behavior, and if it could be used as collaborator in other use cases. But it looks specific to what some space host needs. Maybe we can add these 3 methods in some trait or common superclass, and this could contribute to better readability of the code of hosts and comprehend what happens.