Add a name property to nodes

[dalonsoa]

This seems sensible. As part of this would it be sensible to stop using the class.name as part of the model behaviour and instead make that a default node attribute? I had made this poor decision super early on and since realising that it's not a good idea it has now become all over the place. Maybe it is a separate issue because it seems to me a reasonably large task and the documentation here would need to be updated.

Originally posted by @barneydobson in #60 (comment)

[barneydobson]

Related to this - currently if someone adds a type_ in config that is not a subclass of Node, provided that node_type_override is a subclass, that is fine - and the Model object uses the value in type_ to distinguish that node. You can see this behaviour currently with type_: Foul, i.e., it is not a Node subclass but Model calls it separately in run.

However, this is not very flexible - as, because Foul is not added to the node register, other nodes do not recognise it with function calls such as push_distributed(..., of_type = ['Foul']).

I think it is sensible that the solution for this enables such behaviour as it is an easy way to get a high degree of customisation with minimal coding.

Identified by @RobinMaesPrior