Add Hirose FH-26 generator script

Hirose FH26 series FPC/FFC connectors generator script (based on conn_ffc_molex_502250.py script).

This has been already looked by one of the librarians here: !885 (closed)

I deleted the source branch for the above merge request. I re-created it and this is the new merge request.

Please refer to the previous merge request #885 for details. Many thanks!

The series datasheet:

https://www.hirose.com/en/product/document?clcode=&productname=&series=FH26&documenttype=Catalog&lang=en&documentid=D49355_en

https://www.mouser.com/datasheet/2/185/FH26_catalog-939414.pdf

FH26 series doesn't have 19-pin connector. FH26W series doesn't have 55-pin connector.

This script includes both connectors. FH26W is a halogen-free version of FH26, but the same mechanical dimensions.

Footprints: kicad-footprints!3137 (closed)

3D models (already merged): kicad-packages3D!889 (merged)

3D models FreeCAD parametric source file (already merged): kicad-packages3D-source!369 (merged)