taglibextractortest: Add test for files with empty metadata
Summary:
Indicates a bug in kfilemetadata delivering genre property when genre has no value.
- Copy appropiate sample files to no-meta/
- Remove tag data with picard or kid3
- Create test (of course)
Test Plan: make test
Reviewers: mgallien, Baloo, Frameworks
Reviewed By: mgallien, Baloo
Subscribers: bruns, astippich
Tags: Frameworks, Baloo
Differential Revision: https://phabricator.kde.org/D12028