Replace fields in drill paths

kaitah

We would like to be able to replace existing fields on drill paths with new fields on an existing card.  For example, we may be asked to replace an existing field, `Date`, with a beast mode field for `Quarter`.  Currently we have to go into a card and individually replace each field whenever these change requests happen.  It is a long and tedious process when dealing with a page with many cards, each with 5 or more drill paths.  Our  workaround solution has been to recreate the drill paths on one card, and then recreate the main card itself, which interferes with usage statistic reporting.