Use AnimMgr instead of a custom animation implementation in the ASay module

[snixtho]

Using custom implementation of animations can be slow and uses an unnecessary amount of ManiaScript execution. It is typically better to use the animation manager already built in, which offer higher performance and usually have all the animation types that is needed. It also very easy to use. You can also add delay between animations with the the sleep(milliseconds) function.

Reference for AnimMgr: https://maniascript.boss-bravo.fr/class_c_anim_manager.html