Add seasonal watchlists fetch

# Context Both versions of the MAL API support fetching anime lists per season ([doc](https://myanimelist.net/apiconfig/references/api/v2#operation/anime_season_year_season_get)). As such, we propose to add said functionality to the [MAL Stremio Addon](https://github.com/SageTendo/mal-stremio-addon). The aim of this PR is to make the necessary changes to support seasonal watchlists. # Code changes - Modified _catalog.py_ to support both user and seasonal watchlist fetching; - Updated _manifest.py_ with the seasonal watchlist options and removed unnecessary _genres_; - Fixed missing token bug on _meta.py_; - Added seasonal watchlist configuration support to _ui.py_; - Updated _mal_service.py_ with the newest API; - Modified _config.py_ so that we can configure seasonal watchlist configuration via the UI; - Updated unit tests. # Dependencies This [PR](https://github.com/SageTendo/mal.py/pull/1) should be closed beforehand.