Add Halloween API

[SoSeDiK]

Allow checking / forcing Halloween Season/Day via API. Also makes a tiny optimization over vanilla by using the month/day ints directly (they are stored in fields) instead of fetching from enum.

[kashike]

Is this really needed in the API? This can be re-created in a plugin easily.

[Owen1212055]

Agreed

[SoSeDiK]

Depends. You need to duplicate the perfectly working vanilla system (having another time check, changing equipment on some entities, controlling bat's spawn rules and keeping track of changes in the future) while also not having any communication with other plugins.

I'd love for plugins to be able to add features during Halloween while also providing a ground to control it from one place (Paper's a good source to depend on, unlike some obscure plugin). I don't think maintaining this is much of a pain. Feel free to close if doomed unwanted though.