If two straight edges were selected the chamfer distance would be recalculated so that the length of the straight segment would be equal to `r` (the radius entered by the user). But this was, and is, not done if one or both edges are arcs.
By removing the recalculation code the endpoints of the straight chamfer edge now always match the endpoints of the fillet arc that would be created for the same radius. This also matches the fillet/chamfer behavior in for example Part and Sketcher.
Fixes#11435
Draft_Fillet could already handle arcs, provided they were not Draft_Arcs. The `_extract_edge` function in make_fillet.py had a strange logic, and could also return a wire which would result in problems later.
Another issue was that the `fillet` function in fillets.py did not handle the order of the edges correctly if one of the edges was an arc and the other a straight edge. The arch had to be selected first to prevent this error.
This includes `arcs`, `circle_inversion`, `circles`, `circles_apollonius`,
`circles_incomplete`, `cuboids`, `edges`, `faces`, `fillets`,
`general`, `geometry`, `intersections`, `linear_geometry`,
`offsets`, `sort_edges`, `wires`.
These are added to the `draftgeoutils` Doxygen group so that
the functions contained in each module are listed appropriately
in the automatically generated documentation.
