Port old API tests for products

Make module `test_product_v2` accomplish the same goals as module
`test_product`. Remove the latter module and update the API documentation
accordingly.
> Are names using `cjk` and `latin-1` not allowed, and if so by design, or do we need a BZ here?

I have no idea if cjk or latin1 names are allowed. Those test decorators were in place, and I didn't think too much about them.

> Also, shouldn't we have two different tests, one for random names and another for random descriptions?

We could, but that means copying and pasting code.