Need to replace all instances of list_foo functions either with map functions, or with a new library function

[rkettering]

This is where all the original ones were defined
https://github.com/frogatto/Cube_Trains_Redux/blob/master/data/functions-list.cfg

list_tween can be replaced by lib.math.interpolate
The type signature is slightly different, but we can broadly use it as a drop-in replacement.