Integrate TIME_NS type

[evertlammerts]

Add support for TIME_NS (see duckdb/duckdb#20361).

The original PR added support for the TIME_NS type, which represents the time of day in nanoseconds:

• Arrow supports this type
• Pandas does not have this type itself (but can handle it as an object through arrow)
• Python does not have an equivalent - datetime.time has microsecond precision.

Note that DuckDB supports TIME_NS -> TIME casting but not the other way around, meaning that you can't insert e.g. a datetime.time into a TIME_NS column.