Unify the reflex motion of the Earth correction interface

[DinoBektesevic]

As discussed with Wilson and Colin, the reflex motion of the Earth correction code is in a bit of a state of dissaray with half a dozen implementations. They and I needed a fast vectorized implementation to make searchable collections which got merged in #669 without integration.

This needs some cleanup, which can be deferred for a later date.

[jeremykubica]

I believe this was addressed by some of @maxwest-uw 's work, but feel free to re-open if this is still a problem.