[Cinemeta] Add support for sources other than IMDb

[ArtyIF]

Unfortunately, IMDb's catalogue is a bit poorly organized. For instance, IMDb treats Twin Peaks (2017) as separate of Twin Peaks (1990-1991), while websites like TMDB, Trakt, and Wikipedia, as well as most sources, treat the 2017 series as a season 3 of the 1990-1991 series.

There's also apparently an issue with Futurama's seasons being wrong, according to #316.

So it's clear that IMDb is not a great source for what Stremio and Cinemeta is trying to do. Kodi uses TMDB for its data scraping by default, but it's blocked where I live (Russia), and at least when using a TMDB addon with Stremio the images wouldn't load without a VPN. I suggest using Trakt for the metadata if possible, since Stremio already has an official integration with it, and looking at the API it links to the IMDb tt IDs, so migration won't be as difficult.