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/covermanager/lastfmcoverprovider.h

@@ -37,7 +37,7 @@
 class LastFmCoverProvider : public CoverProvider {
   Q_OBJECT
 
-public:
+ public:
   explicit LastFmCoverProvider(QObject *parent = nullptr);
 
   bool StartSearch(const QString &artist, const QString &album, int id);
@@ -45,10 +45,10 @@ public:
   static const char *kApiKey;
   static const char *kSecret;
 
-private slots:
+ private slots:
   void QueryFinished(QNetworkReply *reply, int id);
 
-private:
+ private:
   QNetworkAccessManager *network_;
   QMap <QNetworkReply *, int> pending_queries_;