benchmarking `pymedm` vs. `pmedm_legacy` performance

#### benchmarking `pymedm` vs. `pmedm_legacy` performance

* attempt benchmarking `pymedm` vs. `pmedm_legacy` performance on equivalent instances
* xref
  *  https://github.com/likeness-pop/pmedm-legacy/issues/9
  * internal `up-usa#-61`
  * #10  