[Feature-Request] Add the option for "Not Watched" in the library #388

[ensapra]

Currently, the library has the watched option, but it doesn't make sense that we cannot sort by unwatched too. Not only that, but it would be nice for those categories to remove the items that don't comply (on watched, remove the watched items, and on unwatched, remove the watched ones)

https://github.com/Stremio/stremio-features/issues/74 https://github.com/Stremio/stremio-features/issues/552 https://github.com/Stremio/stremio-shell/issues/388