Support Fixed-Size Binary and Fixed-Length Byte Array Types in Arrow and Parquet

Why it matters

This feature improves compatibility and type fidelity when exporting and importing fixed-size binary data via Arrow and Parquet formats, ensuring that ClickHouse's FixedString type is correctly matched and handled. It solves issues related to type mismatches and data interpretation during serialization and deserialization.

How to use it

Users can control how the FixedString type is output by adjusting the settings output_format_parquet_fixed_string_as_fixed_byte_array and output_format_arrow_fixed_string_as_fixed_byte_array. These settings determine whether FixedString is exported as fixed-byte array types in Parquet and Arrow formats respectively.