These were floats. Rounding numpy-floats still results in floats so I'm just using int(). The result is rounded down instead of nearest, but the difference is at most 50 nanometres anyway.
Contributes to issue CURA-7501.
When multiplying objects or inserting objects in the scene that do not fit in the buildplate, those
objects would correctly end up outside the buildplate, but their Z position would be aligned at the
absolute Z=0 of the buildplate.
This commit fixes that by compensating in the z-axis, properly moving the object outside the
buildplate in the correct z-position so that it's bottom is aligned with the original object.
CURA-7440
Also improve the filtering a bit so that it's no longer dependent on the order. Doesn't really matter in this case but it should be more robust.
Contributes to issue CURA-7754.
