Remove IRelayMoveInput (#4663)

* Remove IRelayMoveInput

This interface gets called every time a movement key is pressed so it gets called a lot.

* Remove RelayMovementEntityMessage

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

Content.Shared/Movement/Components/IRelayMoveInput.cs

@@ -1,9 +0,0 @@
-using Robust.Shared.Players;
-
-namespace Content.Shared.Movement.Components
-{
-    public interface IRelayMoveInput
-    {
-        void MoveInputPressed(ICommonSession session);
-    }
-}