Healing skeletons by pouring milk over them (and clean pie remains off their skulls) (#21231)

* mvp done - skellies can heal by spillink regular milk on themselves and clean themselves off creaming with water

* added other types of healing milk, also made a separate reaction to oat milk - it has almost no calcium in it

* fixed indent error, made a dumb mistake

Resources/Locale/en-US/species/skeleton.ftl

@@ -0,0 +1,2 @@
+skeleton-healed-by-milk-popup = Calcium restored.
+skeleton-sprayed-by-oat-milk-popup = Feels like fake milk. You feel nothing.

Resources/Prototypes/Entities/Mobs/Species/skeleton.yml

@@ -64,6 +64,40 @@
           - MobMask
         layer:
           - MobLayer
+  - type: Reactive
+    groups:
+      Flammable: [ Touch ]
+      Extinguish: [ Touch ]
+    reactions:
+    - reagents: [ Water, SpaceCleaner ]
+      methods: [ Touch ]
+      effects:
+      - !type:WashCreamPieReaction
+    - reagents: [ Milk, MilkGoat, MilkSoy, MilkSpoiled ]
+      # add new types of milk to reagents as they appear, oat milk isn't on the list
+      # because turns out oat milk has 1/30th the amount of calcium in it compared to the rest
+      # even if it's a meme - I did research
+      methods: [ Touch ]
+      effects: # TODO: when magic is around - make a milk transformation to a skeleton monster
+      - !type:HealthChange
+        scaled: true
+        damage:
+          groups:
+            Burn: -1 # healing obviously up to discussion
+            Brute: -1 # these groups are the only 2 possible ways to damage a skeleton
+      - !type:PopupMessage
+        type: Local
+        visualType: Large
+        messages: [ "skeleton-healed-by-milk-popup" ]
+        probability: 0.25
+    - reagents: [ MilkOat ]
+      methods: [ Touch ]
+      effects:
+        - !type:PopupMessage
+          type: Local
+          visualType: Large
+          messages: [ "skeleton-sprayed-by-oat-milk-popup" ]
+          probability: 0.5
 
 - type: entity
   parent: BaseSpeciesDummy