[format] Follow Parquet list backward-compatibility rules in schema clipping

[juntaozhang]

Purpose

Follow Parquet's backward-compatibility rules for the LIST logical type when clipping Parquet schemas, so that nested variant column pruning and schema conversion correctly distinguish wrapper groups from element types across all standard and legacy list encodings:

• Rule 1: repeated primitive field is the element type.
• Rule 2: repeated group with multiple fields is the element type.
• Rule 3: repeated group whose single child is also repeated is the element type.
• Rule 4: repeated group named array or <list>_tuple is the element type.
• Rule 5: any other repeated group with exactly one non-repeated child is a wrapper; its child is the element type.

Previously the list-structure check did not fully apply these rules, which could misidentify legacy two-level encodings as three-level lists and return the wrong element type during nested variant pruning.

Tests

mvn -pl paimon-format -DwildcardSuites=none -Dtest=ParquetSchemaConverterTest test