Update DataQuality

Changes as discussed in my comment today under
https://github.com/UCHIC/ODM2/pull/23
* moved DataQuality and ResultsDataQuality tables from ODM2Core to
ODM2DataQuality schema
* Changed DataQualityCodeCV to DataQualityCode and made it not nullable
* Removed NormalizationReferenceMaterialValuesID as a foreign key in
Results and implemented a cross-ref table with a 1:1 relationship to
Results.
* Changed: ReferenceMaterials is now directly linked to
SamplingFeatures rather than being a child of Specimens.