Make humans move based on their last grid's angle (#5122)

* Make humans move based on their last grid's angle

* Fix ghost movement, fix weightless grid parenting

* Make sure to init the last grid angle without needing to move

Content.Server/AI/Components/AiControllerComponent.cs

@@ -87,6 +87,8 @@ namespace Content.Server.AI.Components
             }
         }
 
+        public Angle LastGridAngle { get => Angle.Zero; set {} }
+
         /// <inheritdoc />
         [ViewVariables(VVAccess.ReadWrite)]
         public float PushStrength { get; set; } = IMobMoverComponent.PushStrengthDefault;