Lane Anticipation currently triggers on quick steps with lanes. This
changeset makes the "quick" part more dynamic by taking lanes left and
right of the turn into account. The reasoning for this is as follows.
The user can drive on the leftmost or rightmost lane and has to cross
all lanes left or right of the turn, respecitvely.
We scale our threshold appropriately, which now means the threshold
describes the duration the user needs for crossing _a single lane_.
Note: this is a heuristic and assumes the worst case. Which in my
opinion is fine to do since triggering Lane Anticipation in complex
scenarios is desirable.