Add osu! "Aim Assist" mod
Add osu! "Aim Assist" mod

Reference: https://github.com/ppy/osu/pull/5774

LiquidPL/osu-web,notbakaneko/osu-web,ppy/osu-web,nanaya/osu-web,nanaya/osu-web,notbakaneko/osu-web,LiquidPL/osu-web,ppy/osu-web,ppy/osu-web,notbakaneko/osu-web,notbakaneko/osu-web,ppy/osu-web,nanaya/osu-web,notbakaneko/osu-web,LiquidPL/osu-web,LiquidPL/osu-web,nanaya/osu-web,ppy/osu-web,nanaya/osu-web,LiquidPL/osu-web