[CALCITE-7457] VALUES and SELECT produce different validation results for the same expression

[dssysolyatin]

Jira Link

CALCITE-7457

Changes Proposed

• VALUES now routes through validateQuery, triggering TableConstructorNamespace.validateImpl validation (which calls validateValues and inferUnknownTypes). The fix is a validateCall override in SqlValuesOperator.
• inferUnknownTypes no longer descends into subqueries (node.isA(SqlKind.QUERY)). Each query handles its own inferUnknownTypes during its own validation.
• Added additional tests inside existing tests which can be dropped. Just to show that now SELECT and VALUES behaves the same way

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

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