[v0.5.0] Auto Overlaps & Node system rewrite

CHANGES

Node system has been rewritten to make them much simpler. Now, there is only one struct Node that represents
any node in Game Engine, based in NodeType field. At the same time, user interactions with nodes a pretty much the same, with very small changes, if any.

NEW

Auto Overlaps for Node.
Auto Overlap system will build a ComposedOverlap for a Node and all of its children by creating an Overlap with CalculatedSize of the node and position in center of that node for every node in selected node hierarchy.

There is new functions for Node:

• AutoOverlap(bool) - to enable or disable auto overlap.
• AutoOverlapEnabled() bool - to get if auto overlap is enabled for this node.