add bandcamp parser, refactor naming, add type to parse answer

[4www]

Ref: internet4000/radio4000#296

In this PR:

• refactor naming: it is more clear what the functions do, parse, instead of just getting the id.
• type to parse answer: when a url is parsed, it also give a type to the media delivered by this specific provider. For now it is thought as respecting the naming offered by the provider, staying agnostic from media type uniformization (for now at least)
• add bandcamp parser: pass a bandcamp album or track url and it will be parsed to give an id and a type.

{
  url: 'https://iliantape.bandcamp.com/album/it039-andrea-forse',
  provider: 'bandcamp',
  id: 'it039-andrea-forse',
  type: 'album'
}
{
  url: 'https://iliantape.bandcamp.com/track/future-atmo',
  provider: 'bandcamp',
  id: 'future-atmo',
  type: 'track'
}

Not sure what anyone will use that for, but at least it is there and is ready to be used to some applications.

Note: the same way we could add soundcloud, spotify, vimeo etc.

[oskarrough]

LGTM