Add meta data changes support to Factory

For some unit tests it was needed to influence the meta data
of the created descriptions.
Add additional factory options also to create_test_description_json
Make sure Factory created JSON looks like the machinery one

To make comparisons on JSON text level they formation needed
to be equal.
Replace static json data through Factory method

Use create_test_description instead of static json data wherever
possible to make it easier to adapt the tests after format
changes.
Merge pull request #442 from SUSE/optimize_test_structure2

Optimize test structure2