Implement trace as a simple pass through - no logging functionality yet

[Quarz0]

This should just make expressions that have the trace function be able to compile and evaluate without the actual debugging capability of trace

[AlexJSully]

Hi @Quarz0,

Thank you so much for your contribution and for taking the time to implement trace! We truly appreciate your effort and the quality of your work.

At this time, we’re not able to accept public pull requests directly (though we hope to support this soon—stay tuned!). However, we want to make sure great contributions like yours are recognized and included. We’ve have implemented the trace method (#36), and it will be included in the next version release of FHIRPath Go.

Thank you again for helping make this project better!