Update ast subtrees

[andrew-johnson-4]

Describe your changes

Features:

• subtree rewriting should be working for all expressions
• now just need to start porting macros to new macro system

Issue ticket number and link

#1468

Checklist before requesting a review

• [ x ] I have performed a self-review of my code
• [ x ] If it is a new feature, I have added thorough tests.
• [ x ] I agree to release these changes under the terms of the permissive MIT license (1).

1. https://github.com/andrew-johnson-4/lambda-mountain/blob/main/LICENSE