Improve Resource Definition Properties

There are resource definitions, in which some of its property/(s) are either missing, duplicated, or their exact datatypes are not known. These are marked with //FIXME. These require minor to no change at all.

And these FIXME comments go in the resource methods:
getGETModel(Representation)
getCREATEModel(Representation)
getUPDATEModel(Representation)

So to find the correct properties and types for particular resource (eg. CohortMembershipResource2_1.java), one can check in its supportedClass, do a API invocation and check the response etc.

Also, different resource versions can have different properties. Fix and remove those FIXME and make all possible improvements to resource definition properties.