Factory cleanup and start of tab node pills display.

Drawables had the NodeGraphState removed from their constructor arguments.
Some renaming on the HubFactory member variables and class names to be more accurate.

Got rid of the GroupMember class.
Node's and Links are still actully members of Groups.
InputPlugs and OutputPlugs are no longer members of Groups.
You'll need to call get_node to get to the node and then get_group
to get to the group.

The new tab mode will have it's own geo loader and interaction spokes
attached to the root group node. This will make use of the recently added
feature where we can attach mulitple spokes of the same type.