Enhanced Shop Sorting

Extends the vehicle shop with sorting options. The sorting options are (ascending or descending order):
- Name
- Price
- Power
- Max speed
- Weight
To change the shop sorting options, all you need to do is press the "O" key (can be configured) when you have the shop menu open.
In addition, the base game behaviour of grouping mod equipment separately at the end can be toggled on or off (in off mode, mod equipment are blended with the base game equipment according to the sort method).