Node inspector update

• Depth first compute order (enabled by default) instead of breadth first
• Cycle detection in the graph, cyclic nodes are now marked with a compute order of -2
• Added a node create menu when dropping an edge in the graph that also connects the edge to the new node (like in ShaderGraph or VFX Graph)
• Added ITypeAdapter.GetIncompatibleTypes to list all the incompatible types (prevent automatic casting / unwanted connectable ports, can be used to exclude a conversion to System.Object for example)
• Added a node inspector to show advanced settings in the inspector, see ShowInInspector.cs and DrawDefaultInspector(bool fromInspector) for more details.