Support automatic conversion from Uuid (as optional feature)

[Hooksie]

I am implementing types for database objects which use UUIDs as primary keys, from the uuid crate. I noticed there is no automatic conversion for these types to the Python UUID type. Therefor, a pyclass with a UUID field requires a wrapper type.

Given the current features for chrono and decimal, it seems natural to add a uuid feature that implements the type conversion (in this case, similar to the decimal implementation specifically).

If there's interest, I'll take a shot at this. Feels like there's enough prior art in rust_decimal

[davidhewitt]

I think this seems like a reasonable additional optional feature. 👍