[Feature] Implement weapon switching with MouseWheelUp and MouseWheelDown

[blackghost86]

Steps to reproduce:

1. Load Wolf 3D, Spear of Destiny or any of the official Mission Packs (Return to Danger or Ultimate Challenge).
2. Enter Main Menu - Options - Controls Setup - Customize Controls and go down to customize Next / Prev Weapon.
3. Notice that you cannot assign weapon switching to MouseWheelUp and MouseWheelDown.

Affected version: ecwolf-x64-1.4.2-9-g1bff92d