feat(duckDB)!: Add support for shorthand struct array literals in duckDB.

[fivetran-amrutabhimsenayachit]

The current transpilation converts MAX_BY to ARG_MAX but loses struct field names, causing incorrect results in DuckDB.

python3 -c "import sqlglot as sg; print(sg.transpile(\"SELECT MAX_BY(name, score) FROM UNNEST([STRUCT('Alice' AS name, 85 AS score), STRUCT('Bob', 92), STRUCT('Diana', 95)])\", read='bigquery', write='duckdb')[0])"
-->SELECT ARG_MAX(name, score) FROM (SELECT UNNEST([{'name': 'Alice', 'score': 85}, {'_0': 'Bob', '_1': 92}, {'_0': 'Diana', '_1': 95}], max_depth => 2))


duckdb -c "SELECT ARG_MAX(name, score) FROM (SELECT UNNEST([{'name': 'Alice', 'score': 85}, {'_0': 'Bob', '_1': 92}, {'_0': 'Diana', '_1': 95}], max_depth => 2))"
┌────────────────────────┐
│ arg_max("name", score) │
│        varchar         │
├────────────────────────┤
│ Alice                  │
└────────────────────────┘