Support for duration type

[noaccOS]

Documented here

Trying to select on a duration field crashes on Protocol.V*.decode_type not matching

[whatyouhide]

@noaccOS yep this would be very welcome! Any chance you want to make a PR to contribute this? 🙃

[whatyouhide]

Actually, let's hold off on this. Elixir v1.17 will introduce a new Duration struct, so we'll be better off using that for this new type.

Some more info:

• Protocol docs.
• The duration type is only supported in native protocol v5, so it will still not work on previous versions of the native protocol.