New context with albums and lyrics +++ much more

* Added new lyrics provider with lyrics from AudD and API Seeds
* New improved context widget with albums and lyrics
* Fixed playing and context widget getting stuck in play mode when there was an error
* Changed icons for artists in collection, tidal and cover manager
* Removed "search" icon from "Search automatically" checkbox (right click) that looked ugly
* Removed some unused widgets from the src/widgets directory
* Fixed initial size of window and side panel
* Fixed saving window size correctly

src/core/application.h

@@ -51,6 +51,7 @@ class AlbumCoverLoader;
 class CurrentArtLoader;
 class InternetModel;
 class TidalSearch;
+class LyricsProviders;
 
 class Application : public QObject {
   Q_OBJECT
@@ -84,6 +85,8 @@ class Application : public QObject {
   InternetModel *internet_model() const;
   TidalSearch *tidal_search() const;
 
+  LyricsProviders *lyrics_providers() const;
+
   void MoveToNewThread(QObject *object);
   void MoveToThread(QObject *object, QThread *thread);