Improve E029 - ignore when vehicle is close to trip start/end

[barbeau]

Summary:

Based on feedback from agencies, it's more useful to know if position is off-shape in middle of trip, not on way to or from trip (within reason). Some agencies might use this in real-time to create detour alerts, if they could detect that the vehicle was off-route. However, if the driver signs on a bit early, or late, this isn't of interest.

A possible solution to this is to draw a circular buffer around the first and last point of the trip, which has a bigger radius than the trip buffer, and ignore any points within those circles.

Steps to reproduce:

Run validator on trip with vehicle position near start/end

Expected behavior:

Ignore these, focus more on points off the middle of the trip

Observed behavior:

Points near trip start/end are flagged