Fix fillet height for custom divider height

[Stu142]

-Fix for #124

Checks for lower divider height and lowers fillets to match.

If x and y divider heights are different the fillets will only go up to the lower one as they are just and extruded cut and can't differentiate between the different scenarios.

I think this is acceptable as there are probably limited users using both at a different height and it still works.

[greg19]

If x and y divider heights are different the fillets will only go up to the lower one as they are just and extruded cut and can't differentiate between the different scenarios.

The taller fillets should be the ones adjacent to the bin walls that are perpendicular to the higher divider, all other fillets should be shorter.

In code, you can for example:

1. First, iterate over the divider intersections and create 4 fillets that are adjacent to the divider intersection of height $min(h_x, h_y)$ (in a doubly nested for loop).
2. Then create fillets that touch bin walls by two separate for loops
   a. one loop creates fillets that touch $x$-plane wall of the bin with height $h_x$
   b. second loop creates fillets that touch $y$-plane wall of the bin of height $h_y$

[greg19]

Also I think it's a good opportunity to extract the common code of _make_compartments_with_deviders and make_eco_compartments to a helper function, as I see you are making exactly the same changes in these two functions.

[sergebat]

I see refactoring is planned around fillet generation, so let me post it here as this is likely related. Even with the a single divider on a simple gridfinity without a lip (I think this is the culprit) the fillet does not reach the top.

[glenn20]

I see refactoring is planned around fillet generation, so let me post it here as this is likely related. Even with the a single divider on a simple gridfinity without a lip (I think this is the culprit) the fillet does not reach the top.

This effect has been fixed in PR #135 (merged in v0.12.1).