Per-map parallax support (#9786)

* Per-map parallax support

* Comments for future sloth

* c

* bet

* Fix exception

* VV support

* Fix parallax

* mem

* weightless sounds

* Gravity stuff

* placeholder coz im too lazy to stash don't @ me son

* decent clouds

* sky

* Fast parallax

* Imagine spelling

* Loicense

* perish

* Fix weightless status

Co-authored-by: metalgearsloth <metalgearsloth@gmail.com>

Content.Client/Parallax/Data/IParallaxTextureSource.cs

@@ -1,7 +1,5 @@
 using System.Threading;
 using System.Threading.Tasks;
-using System.Collections.Generic;
-using Robust.Shared.Serialization.Manager.Attributes;
 using Robust.Client.Graphics;
 
 namespace Content.Client.Parallax.Data