Create tests for the AllDataProjection and HighDimensionDataTypeResource...

....dataTypeDescription

This change needs to test a number of features for all existing HD data types. The best way to do that would be parametrized tests, but grails 2.4 does not support that. I have now implemented this with an abstract class that is extended for every data type. 

The rnaseq (not _cog) datatype uses such a different structure in its data query that it needs substantial changes before it passes this test. Since it was created by Wim van der Linden and not used in our current branch I have skipped it for now.