KH-211: Changes below:
- Added sql script to remove NOT NULL from koodimetadata and koodistometadata descriptions and shortnames.
- Changed UI to allow empty descriptions and shortnames.
- Removed invalid description and shortname tests from AdminServiceTests and changed the ValidationTest accordingly.
- Changed test data of codesResource/codeElementResource to leave out description and shortname by default.
- Changed the SOAP schema to allow nulls.
Merge branch 'KH-211' of https://github.com/Opetushallitus/koodisto into KH-211