Add Basketball and Basketball Shorts

This PR contains:

- A basketball, which spawns with children and sporting things. It's a high-quality indoors basketball, so it can be made out of leather.
- Basketball shorts, which spawn in generic places (very light, not warm, but covers more than kakhi shorts)
- Both will be used in the basketball player profession, following shortly
- For numbers I used existing items, I believe they should be fine. 
- For spawn-frequency I was not very generous, perhaps should be increased a little