Adds InRangeUnobstructed method to InteractionSystem (#698)

* You cannot pickup items across walls, or pickup items when dead/in crit.

* Adds InRangeUnobstructed method to InteractionSystem.
Changes HandsSystem and ItemComponent to use it.

Content.Server/GameObjects/Components/Mobs/SpeciesComponent.cs

@@ -107,6 +107,11 @@ namespace Content.Server.GameObjects
             return CurrentDamageState.CanDrop();
         }
 
+        bool IActionBlocker.CanPickup()
+        {
+            return CurrentDamageState.CanPickup();
+        }
+
         bool IActionBlocker.CanEmote()
         {
             return CurrentDamageState.CanEmote();