Inconsistent use of length/width in box factories

Hi,

I'm currently using build123 and CadQuery in parallel for pedagocical purposes and differences in behaviour are quite instructive to identify possible problems.

One issue I noticed is that `cadquery.func.box` treats length/width in the opposite way, but I also noticed this is not consistent in CadQuery inernally:

- In OCCT/OCP, `BRepPrimAPI_MakeBox` takes the arguments `dx, dy, dz`. Obviously, it is completely subjective which of `dx` and `dy` to call length or width.
- `Solid.makeBox` takes `length, width, height` and passes them in this order
- `box` takes `w, l, h` and passes them in this order

I think it's confusing that length and width have opposite meaning in these two functions.

If you consider changing it, I would strongly suggest to actually use `length, width, height` (as opposed to `l, w, h`) in both cases for consistency. Independently of whether anything is changed, I also suggest specifying in the doc string which of those dimensions is in x- and which is in y-direction.

Let me know if I can contribute anything.