Beta D/H/T-Series Upfit Tow Hitches 1.3

- Added T-Series upfit options with tow hitch
- Separated all receiver balls from the upfits, making it possible to add other things in the tow hitch slot

Upfit tow hitch is no longer a option in the frame tow hitch. This is due to the Upfit tow hitch showing up also on regular Van/Pickup and Roamer frames.

Flatbed and Cargobox with Tow Hitch are now a separate Upfit option.