Status effect refactor (#4868)

* Oops! All Changes In One Commit

* try desperately to fix prediction issues and fail

* oops

* test

* actually fixes prediction issues

* port jittering to status effect

* default merge behavior + alert cooldown stuff

* silly test issue

* zabloing

* address reviews

Content.Shared/Stunnable/SlowedDownComponent.cs

@@ -0,0 +1,33 @@
+using System;
+using Content.Shared.Movement.Components;
+using Robust.Shared.Analyzers;
+using Robust.Shared.GameObjects;
+using Robust.Shared.GameStates;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Stunnable
+{
+    [RegisterComponent]
+    [NetworkedComponent]
+    [Friend(typeof(SharedStunSystem))]
+    public class SlowedDownComponent : Component, IMoveSpeedModifier
+    {
+        public override string Name => "SlowedDown";
+
+        public float SprintSpeedModifier { get; set; } = 0.5f;
+        public float WalkSpeedModifier { get; set; } = 0.5f;
+    }
+
+    [Serializable, NetSerializable]
+    public class SlowedDownComponentState : ComponentState
+    {
+        public float SprintSpeedModifier { get; set;  }
+        public float WalkSpeedModifier { get; set;  }
+
+        public SlowedDownComponentState(float sprintSpeedModifier, float walkSpeedModifier)
+        {
+            SprintSpeedModifier = sprintSpeedModifier;
+            WalkSpeedModifier = walkSpeedModifier;
+        }
+    }
+}