Given the root of a binary tree, return the length of the longest consecutive path in the tree. A consecutive path is a path where the values of the consecutive nodes in the path differ by one. This path can be either increasing or decreasing. For example, [1,2,3,4] and [4,3,2,1] are both considered valid, but the path [1,2,4,3] is not valid. On the other hand, the path can be in the child-Parent-child order, where not necessarily be parent-child order.