implement a rest-endpoint for medialist

[chinatsu]

i was a little inspired by #488 and decided to spend a little while to make a very rudimentary endpoint for medialist.

the api key used for other integrations is what authorizes the call, though i stuck it into a query parameter rather than part of the url like the other integrations, because i didn't really want something looking like /api/medialist/tv/apikeyhere

i ran into some issues trying to set up every data provider (especially mal), so i haven't been able to test it properly-properly.

during my own testing, i tried using these endpoints in my *arr-stuff, just to see if i could use the endpoint as an import list, and import a tv series and a movie. this is my main motivation to be working on this (hence the camelCase keys.. lol). i believe these integrations ignore unfamiliar keys, so we could definitely expand on the return types, and make it more unified. e.g. this for every media type?

{
    "id": media_id,
    "tvdbId": None if not tvdb_id else tvdb_id,
    "name": name,
    # etc.
}

i'll look into this a little bit, though i'm happy to receive feedback, and i'm also fine having this closed if it's super stupid to add to your codebase!

[FuzzyGrim]

Isn't the response very slow because you are fetching metadata for each media?

[chinatsu]

i haven't tested this branch on any large set of data, so it hasn't been particularly slow for me. i'll give that a shot though, and see how slow it is!
the use case for me requires tvdbId though, but maybe i could conditionally fetch that when it's needed. 🤔

[FuzzyGrim]

I will close this PR in favor of #924