extend MusicAudioTrack constructor to include lyricist and update tests
Summary: extend MusicAudioTrack constructor to include lyricist and update tests
Test Plan: automatic tests are OK
Reviewers: Elisa, astippich
Reviewed By: Elisa, astippich
Subscribers: astippich
Maniphest Tasks: T7883
Differential Revision: https://phabricator.kde.org/D12548