refactor(TripDetails): use UpcomingDepartures vehicle if same trip

[thecristen]

Scope

Asana Ticket: [SF/UD] Trip Details: Hide predictions for stops that the vehicle has already visited

Implementation

A refactor I did to make this easier -- The vehicle used in UpcomingDepartures is already matched to the predicted schedule's stop and stop sequence -- if it also is on the predicted schedule's trip (as opposed to a prior trip or some such), we can pass it into TripDetails directly and do the rest.
The actual task -- in the last commit, I adjust the logic to remove any prior trip stops based on the vehicle location (basically option B in the Asana ticket).

Screenshots

How to test

Since this was an intermittently-seen problem I'm not sure how to reliably reproduce, but I remember seeing it on the 9 bus semi-often...