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.Server/Physics/Controllers/MoverController.cs

@@ -4,6 +4,7 @@ using Content.Server.Shuttles.Systems;
 using Content.Shared.Vehicle.Components;
 using Content.Shared.Movement;
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.Systems;
 using Content.Shared.Shuttles.Components;
 using Robust.Shared.Map;
 using Robust.Shared.Player;