feat(xanthous): Gormlaks yell in gormlak when they see the character

Add a new "greetedCharacter" field to the creature hippocampus type,
which tracks whether or not that creature has greeted the character
yet. In the gormlak AI, when the gormlak sees the character and starts
running towards them, if that field is set to False send a message that
says that the gormlak yells a single randomly-generated gormlak word at
the character, then set the field to true

The gormlak yells "gukblom"!

Change-Id: I17a388393693a322c2e09390884ed718911b2fc4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3207
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI

users/grfn/xanthous/src/Xanthous/Entities/Creature/Hippocampus.hs

@@ -7,6 +7,7 @@ module Xanthous.Entities.Creature.Hippocampus
   , initialHippocampus
     -- ** Lenses
   , destination
+  , greetedCharacter
     -- ** Destination
   , Destination(..)
   , destinationFromPos
@@ -50,7 +51,11 @@ destinationFromPos _destinationPosition =
   in Destination{..}
 
 data Hippocampus = Hippocampus
-  { _destination :: !(Maybe Destination)
+  { _destination      :: !(Maybe Destination)
+  , -- | Has this creature greeted the character in any way yet?
+    --
+    -- Some creature types ignore this field
+    _greetedCharacter :: !Bool
   }
   deriving stock (Eq, Show, Ord, Generic)
   deriving anyclass (NFData, CoArbitrary, Function)
@@ -61,4 +66,7 @@ data Hippocampus = Hippocampus
 makeLenses ''Hippocampus
 
 initialHippocampus :: Hippocampus
-initialHippocampus = Hippocampus Nothing
+initialHippocampus = Hippocampus
+  { _destination      = Nothing
+  , _greetedCharacter = False
+  }

users/grfn/xanthous/src/Xanthous/Entities/RawTypes.hs

@@ -37,6 +37,7 @@ module Xanthous.Entities.RawTypes
   , HasLongDescription(..)
   , HasMaxHitpoints(..)
   , HasName(..)
+  , HasSayVerb(..)
   , HasSpeed(..)
   , HasWieldable(..)
   ) where
@@ -80,6 +81,8 @@ data CreatureType = CreatureType
   , _friendly     :: !Bool
   , _speed        :: !TicksPerTile
   , _language     :: !(Maybe LanguageName)
+  , _sayVerb      :: Text -- ^ The verb, in present tense, for when the creature
+                         --   says something
   }
   deriving stock (Show, Eq, Ord, Generic)
   deriving anyclass (NFData, CoArbitrary, Function)

users/grfn/xanthous/src/Xanthous/Entities/Raws/gormlak.yaml

@@ -12,3 +12,4 @@ Creature:
   speed: 125
   friendly: false
   language: Gormlak
+  sayVerb: yells