Split forw and backw columns in routability tests for routability and speed

[TheMarex]

Currently the forw and backw columns allow binary values such as x vs. but also speed values such as 5 km/h. This becomes complicates once you introduce weights for routing because typically you want to test rate not speed of those.

So we should split forw and backw into: forw_speed, backw_speed, forw_rate, backw_rate.