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/GameObjects/Components/Nutrition/DrinkComponent.cs

@@ -44,7 +44,7 @@ namespace Content.Server.GameObjects.Components.Nutrition
         [ViewVariables]
         public ReagentUnit TransferAmount { get; private set; } = ReagentUnit.New(2);
         [ViewVariables]
-        protected bool Opened { get; set; }
+        public bool Opened { get; protected set; }
         [ViewVariables]
         public bool Empty => _contents.CurrentVolume.Float() <= 0;