feat: Three new mods

[IcedDog]

Added three new mods.

[liquidhelium]

需要改一下高速模式的代码，其他看着没问题
(如果说其在设计上就是为了强制玩家使用1.5速，那这个名字不太合适也许？因为对于2速玩家反而是低速)

[Mivik]

Run cargo fmt plz

[IcedDog]

需要改一下高速模式的代码，其他看着没问题 (如果说其在设计上就是为了强制玩家使用1.5速，那这个名字不太合适也许？因为对于2速玩家反而是低速)

我改成了在原来速度的基础上乘1.5。但是我是希望设置和模组是区分开来的，后面结算界面上应当正常显示设置的速度，并在（将来可能有的）开启的模组列表显示里面显示开启了Nightcore模组。

[Mivik]

LGTM, thanks for your contribution!

Already resolved

[YuevUwU]

Behavior Changes

• Add mod icons, displaying on ending scene
• "Fade Out" mod is now really "Fade" (by changing alpha) instead of hiding immediately (Still apply alpha to the whole note)
• (And Later...) "Fade Out" mod effects no longer apply on fake note (#720)

New

• Add 3 mods:
  • Fade In: (mutually exclusive with "Fade Out" mod)
  • Nightcore: Speed of chart and music will be 1.5 * [Settings > Chart > Speed] (with increasing pitch as usual)
  • Rainbow: Note and Judgeline will have hue changes