Added 3D for Bourns SRU8028.

[cnieves1]

Datasheet: https://bourns.com/docs/product-datasheets/sru8028.pdf
Source: KiCad/kicad-packages3D-source#278
Footprint: KiCad/kicad-footprints#2237

---

Thanks for creating a pull request to contribute to the KiCad libraries! To speed up integration of your PR, please check the following items as you complete them:

• A screenshot of the model(s) aligned with KiCad footprints is very useful
• Was the 3D model(s) created in a mechanical modelling program?
• Source files (or scripts) have been contributed
• Step model submitted in 1:1 scale
• WRL model submitted in 1:2.54 scale
• 3D model alignment checked against KiCad footprint
• WRL model uses correct material properties
• Geometry check performed against mechanical models

[Franck78]

Why is this thing still 'open' when the footprint submitted for it is merged ?

• no obvious visual defect
• no request from anyone