Moved query classes from dir optimizers into new dir dp_query. Added NormalizedQuery class for queries that divide the output of another query by a constant like GaussianAverageQuery.
PiperOrigin-RevId: 240167115
tf.nest.map_structure_up_to has changed so that map_structure_up_to(x, func, x, y) no longer raises an error when y is longer than x, for example x=[1,2], y=[1,2,3]. This broke one of our tests for nested query. Remove the test until (if and when) the old, more reasonable, behavior is restored.
PiperOrigin-RevId: 232057385
1. Rename PrivateQuery to DPQuery.
2. Move construction of DPQuery to outside of optimizer.
3. Remove PrivateAverageQuery and PrivateSumQuery, and rename DPQuery's 'get_query_result' method to 'get_noised_result'. Rename private_queries.py to dp_query.py.
4. Remove thrice-replicated run_query function from the test classes and replace with a single function in new test_utils.py.
5. Add functions gaussian_sum_query_from_noise_multplier and gaussian_average_query_from_noise_multplier.
PiperOrigin-RevId: 230595991
