Add exact-fit strict-inequality/range aggregate check functions (is_aggr_greater_than, is_aggr_less_than, is_aggr_in_range, is_aggr_not_in_range) #1495

Context

Follow-up from review on PR #1485 (ODCS type: library quality metric support): comment.

DQX's type: library data-contract rule generator maps ODCS quality metrics (rowCount, nullValues, missingValues, invalidValues, duplicateValues) onto DQX aggregate checks where possible. Four of the eight ODCS threshold fields have no exact-fit DQX aggregate check today, so the generator falls back to a dataset-level sql_query check instead:

• mustBeGreaterThan (metric > X)
• mustBeLessThan (metric < X)
• mustBeBetween (lo < metric < hi, both bounds exclusive per ODCS)
• mustNotBeBetween (metric <= lo OR metric >= hi, per ODCS's exclusive-bounds semantics)

Proposal

Add native DQX check functions for these, so the data-contract generator (and any other caller) can use a structured, exact-fit check instead of a raw SQL string:

• is_aggr_greater_than(column, limit, aggr_type=..., ...)
• is_aggr_less_than(column, limit, aggr_type=..., ...)
• is_aggr_in_range(column, min_limit, max_limit, aggr_type=..., ...) (exclusive bounds)
• is_aggr_not_in_range(column, min_limit, max_limit, aggr_type=..., ...) (exclusive bounds)

These would mirror the existing is_aggr_equal / is_aggr_not_equal / is_aggr_not_less_than / is_aggr_not_greater_than family in check_funcs.py (same aggr_type, group_by, row_filter, tolerance parameters, etc.), and the DataContractRulesGenerator in contract_rules_generator.py could then replace its sql_query fallback for these four ODCS threshold fields with the new structured checks.

Out of scope for this issue

The generated sql_query fallback that's in place today is reviewed and correct — this is a nice-to-have follow-up to make the generated rules more structured, not a bug fix.