Add an Active indicator for NDCs using RxNorm Historical

[jrlegrand]

Problem Statement

If NDC comes from RxNorm Historical and is not used / reused elsewhere, look to the end_date column to determine if it's still active.

Criteria for Success

Additional column in the all_ndc_descriptions mart for active_yn.

Additional Information

Maybe compare RXCUIs to make sure the NDC wasn't reused and may be active again?