fix(search): make FalkorDB tie-breaking deterministic

[jaimehgb]

Summary

• add UUID ascending as the secondary order for all seven score-ranked FalkorDB search primitives
• make reciprocal rank fusion break equal scores by UUID
• mirror query ordering in the FalkorDB SearchOperations implementation

This prevents database iteration order and input insertion order from changing capped search results when scores tie.

Tests

• added focused query-rendering coverage for the legacy and SearchOperations paths
• added an equal-score RRF regression test
• pytest --confcutdir tests/utils/search tests/utils/search/deterministic_tie_breaks_test.py tests/utils/search/search_utils_test.py -q (20 passed)

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[Naseem77]

@jaimehgb Reproduced the nondeterminism: the same 6 tied-score nodes inserted in different orders came back in different orders, and with your patch both come back in identical UUID order. 15 tests pass. Only thing left is a ruff format run on the test file (that's the failing check) and the CLA.