implement different types of LyricsProviders

[pschichtel]

Currently the plugin only supports static access of websites, but many websites require to search for the songs as the URLs contain IDs.
Also there are websites that provide public APIs where we don''t need complicated and error prune content processing.

implementation ideas:

public interface LyricsProviderFactory<T extends LyricsProvider>
{
    T newLyricsProvider(YamlMappingNode configuration);
}

name: 'xy-lyrics.com'
type: 'static'
config:
    url: 'blabla'
    pattern: '<div>(?<lyrics>.*?)</div>'
    filters:
    - filter_a
    - filter_b

name: 'xy-lyrics-search.com'
type: 'search'
config:
    search-url: 'blabla'
    url-pattern: '<a href="(?<url>.*?)">{artist}-{name}'
    filters:
    - filter_a
    - filter_b

name: 'api.xy-lyrics.com'
type: 'api'
config:
    url: 'http://api.lyrics.tld/v3/lyrics/{artist}/{title}'
    data-path: 'lyrics.text'