Disable speaking while unconscious/dead (#362)

* Disable speaking while unconscious/dead

Fixes #359

* Add CanSpeak ActionBlocker

Matches the existing technique for other actions like CanUse() and CanThrow().

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

@@ -51,6 +51,11 @@ namespace Content.Server.GameObjects
         {
             return true;
         }
+
+        bool IActionBlocker.CanSpeak()
+        {
+            return true;
+        }
     }
 
     /// <summary>
@@ -87,6 +92,11 @@ namespace Content.Server.GameObjects
         {
             return false;
         }
+
+        bool IActionBlocker.CanSpeak()
+        {
+            return false;
+        }
     }
 
     /// <summary>
@@ -133,5 +143,10 @@ namespace Content.Server.GameObjects
         {
             return false;
         }
+
+        bool IActionBlocker.CanSpeak()
+        {
+            return false;
+        }
     }
 }