Component intersections outside parent/child relations for fused IGES exports

[CLiersch]

Currently (TiGL V3.2.3), the fused IGES export from TiGL considers intersections between two components only, if they have a parent/child relation: -> Imagine, you have two wings: an HTP and a VTP, both defined with the same fuselage as parent. -> If you call the fused IGES export, you get a boolean addition of the fuselage solid body with both of the wing solid bodies. But if HTP and VTP do also intersect each other, then the procedure fails and either VTP or HTP is missing in the output

Proposed solution: Consider the intersections between all elements when performing the boolean addition, instead of using only parent/child relations.