ATLAS-2229: ValueArray clause implementation.

ATLAS-2229: DSL valueArray clause, added unit tests.

ATLAS-2229: DSLVisitor refactoring.

ATLAS-2229: Fixed REST call with classification.

ATLAS-2229: GroupBy, Select, Min, Max, Count

ATLAS-2229: Additional unit tests for min, max, count. Updated test framework.

ATLAS-2229: Handling case where query is invalid.

ATLAS-2229: Updates related to boolean value handling.

ATLAS-2229: Count, Sum, Max, Min operations implemented.

ATLAS-2229: Addressed review comments.
Signed-off-by: apoorvnaik <apoorvnaik@apache.org>