addSubNode

Will add subnode in tree if there are no any node with newData

• If newData is greater than SortedBinaryTreeNode.data of currently checking node, will be used SortedBinaryTreeNode.rightNode

• If newData is equal to SortedBinaryTreeNode.data of currently checking node - will be returned currently checking node

• If newData is less than SortedBinaryTreeNode.data of currently checking node - will be used SortedBinaryTreeNode.leftNode

This process will continue until function will not find place to put SortedBinaryTreeNode with data or SortedBinaryTreeNode with SortedBinaryTreeNode.data same as newData will be found