MAGN-4745 Colour the nodes according to the delta state

The users have no idea of Node execution plan, when a value of a node is changed.

This fix address the node execution plan. When Show Node Execution is set on the Debug menu, 
users can see the nodes with Green boundary, meaning those nodes will be executed on the next run. 
Nodes will retain its original state after the run. 

- [ ] @lukechurch 
- [ ] @junmendoza 
- [ ] @ikeough 
We can't push more state into the engine controller without a really good reason. The preview calls are supposed to be pure, they compute a value and hand it back. It's not good practice to store that on the object.