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/player.cpp

@@ -431,6 +431,7 @@ void Player::EngineStateChanged(Engine::State state) {
       emit Playing();
       break;
     case Engine::Error:
+      emit Error();
     case Engine::Empty:
     case Engine::Idle:
       emit Stopped();