Clean up scars.yml and add a new chest scar (#25215)

add

Resources/Textures/Mobs/Customization/scars.rsi/meta.json

@@ -22,6 +22,10 @@
     {
         "name": "scar_top_surgery_long",
         "directions": 4
+    },
+    {
+        "name": "scar_chest",
+        "directions": 4
     }
   ]
 }