Convert BehaviourToolKit to use resources and graphic edit

[Shadowblitz16]

Convert BehaviourToolKit to use resources and graphic edit

[ThePat02]

In short: There are way to many benefits of just keeping them as nodes. They are easier to edit, extend and use. You are however free to make your own fork and implement these things by yourself, but the plugin is heading in another direction, as one of the next big PRs will allow users to dynamically move nodes around at runtime. #47

Parent a child relationships could be staticly typed. (no more adding a Transition node as a child to another transition node only State nodes)

When are you doing this? Transition Nodes should only be children of State nodes.

Actor signals and properties could be type checked.

This can be done now by using something like actor = actor as CharacterBody2D.

AnimationTree could possibility be used as the node. aka behaviour toolkit root could extended AnimationTreeRoot

No, this is not possible. You would have to build your own Control.