AI pickup changes (#1811)

* AI pickup changes

Eating and drinking isn't spammed anymore.
AI can do InRangeUnobstructed checks for item pickups.
AI can open drink cans.

AI littering to be coded.

* #nullable enable

* github's nullable fails are actively shortening my lifespan

* Use a const instead

So it's easier to find given the performance implications.

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

Content.Server/AI/Utility/Actions/Nutrition/Food/UseFoodInInventory.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using Content.Server.AI.Operators;
 using Content.Server.AI.Operators.Inventory;
+using Content.Server.AI.Operators.Nutrition;
 using Content.Server.AI.Utility.Considerations;
 using Content.Server.AI.Utility.Considerations.Inventory;
 using Content.Server.AI.Utility.Considerations.Nutrition.Food;
@@ -27,7 +28,7 @@ namespace Content.Server.AI.Utility.Actions.Nutrition.Food
             ActionOperators = new Queue<AiOperator>(new AiOperator[]
             {
                 new EquipEntityOperator(Owner, _entity),
-                new UseItemInHandsOperator(Owner, _entity),
+                new UseFoodInInventoryOperator(Owner, _entity), 
             });
         }