Tracing of Julia programs

An alternative to writing down syntax trees with macros is to either:

- Use `@code_lowered` to expand a julia function, and then parse into Trm/e-graph from that
- Pass in something that subtypes `Number` to a julia function, and have the operations on it accumulate a syntax tree instead of computing anything

We should think about both of these approaches. Both of these are used in `SciML`: the second one is the default mode of operation and the first one is supported through https://docs.sciml.ai/ModelingToolkit/stable/tutorials/modelingtoolkitize/