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