[FEATURE] - IW3: Display RPG angle when firing the rpg

[Aldori15]

Currently the 3xp CJ server on PC does this where when firing an RPG, it will display the rpg angle at the bottom left of the screen. See screenshot below.

I think by adding another config option to the IW3 menu for toggling rpg angle, this could be good when going for rpg strafes or height bounces by making sure the angle is good. Looking all the way down at the ground would be considered a "best" rpg with an angle of 85 and looking all the way up at the sky would be considered a "worst" rpg with an angle of -85.