Add method to retrieve album by upc

[Ihsahn]

Deezer supports album retrieval by providing upc instead of it's (deezers) id, eg: https://api.deezer.com/album/upc:724384960650

I would like to add support for that.

Proposed changes:

• [ ] introduce new pub trait DeezerUpcObject and with a method get_by_upc(upc: &str)
• [ ] implement it for Album, so following code would work:

  let album = Album::get_by_upc("724384960650").await?.unwrap();

• [ ] add album_by_upc(&self, upc: &str) method to DeezerClient

@maxjoehnk I am willing to do the work, just would like to know your opinion first.

[maxjoehnk]

Api wise this looks fine we could think about a different client method, maybe an enum with an Id and a Upc variant. Do you know of more apis that we should consider?

[Ihsahn]

You can also query track by isrc, like: https://api.deezer.com/track/isrc:GBDUW0000059. I am not aware of any other ids/apis that could be used like that.

[maxjoehnk]

Then I would like an enum with an Isrc and a Upc variant and a method album_by_code or something similar.