values implements Postgres's VALUES construct and allows you
to create a SELECT that consists of the given rows.
Example type specialization:
values :: [(Field a, Field b)] -> Select (Field a, Field b)
Assuming the makeAdaptorAndInstanceInferrable splice has been run for the
product type Foo:
values :: [Foo (Field a) (Field b) (Field c)] -> S.Select (Foo (Field a) (Field b) (Field c))