TriggeredHEROCamera and TriggeredRPC Camera overlapping functionality

#71 introduced a new TriggeredHEROCamera to be compatible with a more general workflow we implemented in the HEROs devices drivers (see !89). However the functionality is the same as the TriggeredRPCCamera only differing in some function calls. I think it does not make sense to maintain both classes as it may lead to further confusion.

We should think about how to unify them and if we can deprecate one of them. I like the name TriggeredRPCCamera more because it also includes non-HERO rpc cameras, on the other hand we should not encourage people to do non-HERO rpc calls...