Draft: Add Samtec ST4 generators

First draft of Samtec ST4 0.4mm dual headers.

Mating part to !901

• Print: https://suddendocs.samtec.com/prints/st4-xx-x.xx-x-d-x-xx-xr-mkt.pdf
• Footprint: https://suddendocs.samtec.com/prints/ss4-xx-x.xx-x-d-x-xx-tr-footprint.pdf
• Series page: https://www.samtec.com/products/st4

Fit up with Samtec STEP:

Draft while I think about if the generator needs any adjustments here.