Limit CuBIDS filename changes to the `acq` entity and datatype folder

[tsalo]

Summary

Currently, CuBIDS has the entities that may exist in output filenames hardcoded. If we instead choose to limit CuBIDS to the acq entity (which is how we label variants), then we can just use whatever entities were in the original filenames.

This will primarily affect CuBIDS.change_filename. I'm not sure how it would impact the key/parameter/acquisition group grouping process.

Additional details

Simpler code, more generalizability.

[mattcieslak]

Discussed at informatics meeting 2/12/24, we agree