Jetpacks (#9023)

* Movement acceleration

* tweaks

* Weightless refactor coz fuck it

* CCVars

* weightless movement tweaks

* Some cleanup while I'm here

* dorkpacks

* thanks fork

* fixes

* zoomies

* toggles

* hmm

* yamls

* b

* so true

* Effects refactor

* namespace

* review

Content.Shared/Friction/SharedTileFrictionController.cs

@@ -1,6 +1,7 @@
 using Content.Shared.CCVar;
 using Content.Shared.Movement;
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.Systems;
 using JetBrains.Annotations;
 using Robust.Shared.Configuration;
 using Robust.Shared.GameStates;