This changes the IGES import parameter precision to be file-defined
instead of hard-coded in KiCad. OCE-0.18 does not handle faces with
a set of points whose approximation creates a single point.
By allowing the file to set the precision level, we leave it to the
generating program to create a file with non-degenerate faces.
Fixes: lp:1738872
* https://bugs.launchpad.net/kicad/+bug/1738872