Exporting the Bill of Materials uses the netlist exporter. Both of
these routines were stripping the extension, leading to projects like
"test.project.kicad_pro" having the project name stripped. We separate
the BOM netlist export from generic plugin netlist export to allow the
correct behavior when exporting netlists and generating BOMs
Fixes https://gitlab.com/kicad/code/kicad/issues/10270
(cherry picked from commit bef762e652)
30549a5e6a