Regen VersionGroupPokemonMoveMethods when loading the database
Regen VersionGroupPokemonMoveMethods when loading the database

Instead of relying on people to remember to run a script to regenerate
it, just do it automatically at load time. Only takes a couple seconds.
And hey, this gives us a free test too! (CI will complain if load+dump
isn't clean.)

Fixes #334
Fixes #74

veekun/pokedex,veekun/pokedex