Scalar value conversion for decoded DuckDB vectors.
Converts fixed-width physical values into Elixir terms such as booleans, integers, floats, Date, DateTime, Decimal, and tagged DuckDB intervals.
Date
DateTime
Decimal
@spec decode_fixed(binary(), map(), atom()) :: QuackDB.Protocol.Reader.read_result(term())
@spec decode_sequence(map(), integer()) :: term()