Remove MediaSources field from listings

[lostb1t]

Mediasources is set as an minimal field here: https://github.com/jellyfin/Swiftfin/blob/main/Shared/Extensions/JellyfinAPI/ItemFields.swift

This is fine for detail pages but for listings this can slow down responses significantly, especially when having multiple versions. And As far as i can tell this data is unused for listings

[JPKribs]

As far as I'm aware, media sources can only be obtained via that API. So we'd be re-calling the same API again to get the media sources, duplicating some efforts. If there was some getItemMediaSources I think this would be a no-brainer.

Not opposed to this an idea but my concern is we'd be duplicating some API calls and we'd have to track down all usages of MediaSources and add in a secondary call. We'd also have to build in some logic to ensure that, once called, we're avoiding running this new secondary call for items that already have this media source.

Removing this would require some additional work aside from removing it from the let. And unfortunately, since the MediaSources object is nullable, identifying what specifically breaks with this change wouldn't be immediately visible. Since, most instances already have catches/placeholders to handle where they don't exist.

This all being said, I'd recommend anyone interested in researching this hold off until the Player rewrite is done. From what I remember, the player is the most common usage of MediaSources so these are subject to change with the player.

[lostb1t]

As far as i can see the detail page currently does a separate call to get the details and mediasources regardless of the listing. So nothing will change there.

[LePips]

At least now, we do take advantage that media sources are already retrieved (via specifying that field) for launching episodes to the video player from the series page and launching channels.

In #1581 we now retrieve the full item when building the media player item, so when a media source isn't given we just use the first media source - which has been what's used anyways in these scenarios.

Example doing that for episodes: b8db075

Taking a look at all of this again, I think we can remove the minimum fields entirely. Retrieving the overview and taglines were from a very old design idea of using a skeleton loading view for the item and the amount of data that is given to us by default (specifying no fields) is sufficient for "minimum usage". My only concern was the parentID for episode-series images, but we are given that by default (and should probably use the parent tags anyways).

But as stated by Joe, when this happens (after #1581) just making sure we also change how the items are passed into the media player. That would just surface as a non-interactive tap, so it would be easily workable.

[JPKribs]

Since #1581 is completed, this should be eligible to be worked on.