Don't allow queries with 'IN' predicate with an empty sequence

While SQLalchemy-based storage tests running
(test_storage_scenarios.test_query_filter_with_empty_in) there was
invoked SAWarning: The IN-predicate on "sample.resource_id" with
an empty sequence.

Reason is in not checking of 'in' query lists elements number.
These queries make no sense, so JSON Schema for this was fixed.

Change-Id: I43ea2d20269c9567b3ef99936f63b7c0003170df
Merge "Don't allow queries with 'IN' predicate with an empty sequence"