`spin:postgres@4.0.0` interface

[itowlson]

Will ship in Spin 3.4. Adds UUID, JSONB, range, array, and interval data types.

[adamreese]

IIRC, This will need to be part of wasip2 branch because the wits for the current SDK are locked until we are on the new bindings generator.

[adamreese]

Completed in #61