Allow user to choose between the 4:3 or 16:9 weapon group buttons alignment

[BC46]

mod_options.iss, line 899:

// The position of the Weapon Group buttons is hardcoded. Currently we only support the correct position for 4:3 and 16:9 aspect ratios.
// By default it's set to 4:3, and by changing HudWeaponGroups in HudShift.ini to true, it'll be set to 16:9.
// The 16:9 position will only be set if the resolution is NOT 4:3, because it's possible that people with other aspect ratios will disregard the warning.
if not IsDesktopRes4By3() then
        FileReplaceString(HudShiftPath, ';HudWeaponGroups = true', 'HudWeaponGroups = true');

This code automatically determines which alignment to use based on the user's screen aspect ratio. This is nice, but it's possible that a user with a 16:9 monitor wants to play in 4:3. In this case, the 16:9 alignment will be used while that's not the right one. Therefore, it'd be better if the user could choose between the 4:3 and 16:9 alignment with the help of a few radio buttons in the installer.