Basic gibbing (#2973)

* Adds gibbing

* Adds adminbused absurd-damage foamblade

* Sane parts

* BaseOrgan -> BaseMechanism

* Do not do random offset on shared, fix killing oneself with click attacks

* BaseMechanism -> BaseHumanOrgan -> *stuff*

* Account for prediction, again

* Add gibbing sound

Content.Shared/GameObjects/Components/Body/IBody.cs

@@ -247,5 +247,10 @@ namespace Content.Shared.GameObjects.Components.Body
         /// <param name="index">The index to look in.</param>
         /// <returns>A pair of the part name and body part occupying it.</returns>
         KeyValuePair<string, IBodyPart> PartAt(int index);
+
+        /// <summary>
+        ///     Gibs this body.
+        /// </summary>
+        void Gib(bool gibParts = false);
     }
 }