Implement more tags for taglib writer

Summary:
Implement more tags for writing for the
taglib writer including composer, disc number,
album artist, lyricist, conductor, lyrics,
copyright and language.

Test Plan: tests pass

Reviewers: bruns, mgallien, ngraham

Reviewed By: ngraham

Subscribers: kde-frameworks-devel, Baloo

Tags: Frameworks, Baloo

Differential Revision: https://phabricator.kde.org/D18603