R1:a94528ee4aa1

Expose Differential actions for "transaction.search" in a basic way

Summary:
See PHI725. Ref T13151. These actions are somewhat unusual and I considered different ways to represent them (make them look like "status" transactions; build multiple synthetic transactions) but ultimately landed on the simplest approach of just exposing them more or less as they exist internally.

I haven't included data for any of them. Most don't really have any data, but "accept" does. I'm holding off on providing more data…