Feature: Decouples VA filter from the title language, and moves to the new Anilist StaffLanguage API key

[mmshivesh]

This PR fixes #58, and improves the behavior of #32 (paging @As4shi since I found their fork mentioned here which is a very similar independent implementation of this.)

Now, there's a separate selector with an option to choose between JP, non-JP, and "Do not Filter" options. The default choice is "Do not Filter":

Additionally, there's changes the GraphQL query to reference the new languageV2 key and corresponding code changes to make Language choice independent from Title/Original Title choices.

https://github.com/mmshivesh/jellyfin-plugin-anilist/blob/f05f38e77542bb425bfbd7b0748c8158d606ebb5/Jellyfin.Plugin.AniList/Providers/AniList/AniListApi.cs#L132

A built .dll of this version can be found on the fork here: https://github.com/mmshivesh/jellyfin-plugin-anilist/actions/runs/8864938203

Testing:

• The test action was run, and passed successfully.
• Have been personally using this version and did a full metadata refresh of my library to perfect results.

Future Work:

• This also lays groundwork to let users filter VAs on the basis of any language (maybe with an Include/Exclude these languages box?)

Note: Basing this off of Unstable branch