Add "diff" functionality

[ChosunOne]

Is your feature request related to a problem? Please describe.
Comparing elements of two trees, or of multiple versions of the same tree, requires a lot of boilerplate code to accomplish and is inefficient.

Describe the solution you'd like
Adding a "diff" function to compare two trees would make comparing trees far more efficient, as having access to the internal structure of the default tree only needs to look at the locations.

Describe alternatives you've considered
It is currently possible to build a structure with a diff function, but adding it to the default tree structure would enhance the usability of the crate immensely.

Additional context
With this feature, it could allow for the efficient merging of two trees.