Absorb uniqName in uniqCond

[hgiesel]

Biggest drawback is that generators cannot longer drop items after not being successful.
There needs to be some communication between the validator and the generator:

• if the validation failed because of a uniqueness constraint: drop, otherwise, keep.

[hgiesel]

Rather than merging, test uniqNames separately, and return a special value, indicating whether a rejection came from uniqName, or from uniqCond.