[CALCITE-7453] Preserve duplicate output names through star expansion and report resulting ambiguity correctly

[nirmal-e6]

Jira Link

CALCITE-7453

Changes Proposed

• Preserve duplicate visible output names during SELECT * expansion instead of uniquifying them.
• Carry exact source-field metadata for star-expanded duplicate columns so later validation and conversion do not rebind by name to the wrong field.
• Use that exact metadata in qualification, type derivation, rolled-up column checks, ORDER BY resolution, and SqlToRel field access.
• Report ambiguity when preserved duplicate output names make outer references genuinely ambiguous.
• Update affected validator, converter, runtime, and baseline tests to reflect preserved duplicate names and corrected EXPR$N ordinals.