Add 3D Model for ESP32-S2-SOLO

[marcidy]

Please update the ESP32-S2-SOLO footprint to include a reference to the 3D model.

Since it's geometrically compatible with the WROOM, I modified a local copy to include:

  (model "${ESPRESSIF_3DMODELS}/ESP32-S3-WROOM-1.STEP"
    (opacity 0.7500)    (offset (xyz -9 -9.75 0))
    (scale (xyz 1 1 1))
    (rotate (xyz 0 0 0))
  )

which worked for my purposes

e.g., from KiCAD:

Thanks!