Motivation behind this class split is to enable different behaviors for NPCs in the bestiary vs those in the encounter.

Most notably bestiary NPCs have some detailed user defined description.

Removes the odd behavior of the nickname copying the name if no nickname was given. Using None makes it more clear that the nickname is missing entirely.

This does make it impossible to remove a nickname once given though.

Replaces old NPC tests with combat NPC tests.

Still need bestiary NPC tests.

Allows defining the reset and empty behaviors within the class itself.

With the split between NPC types, info is a much more helpful command so info all is a useful tool.

The isValidInt method already checks a whole list of values, so there is no need to loop over them as done before.

Removes duplicates and sort the selection. Ideally would only remove the duplicates.