Enhance minMap and maxMap to include zero values in results, addressing issue #16087.

Why it matters

Previously, the minMap and maxMap functions would skip zero values when calculating their results, which could lead to inaccurate outputs. This fix ensures that zero values are correctly considered, providing more accurate and expected aggregation results.

How to use it

To benefit from this improvement, users just need to upgrade to the ClickHouse version including this fix. No changes to query syntax or function usage are required; the behavior of minMap and maxMap will automatically include zero values in their computations.