UUID v4 generator for non-secure contexts?

**Is your feature request related to a problem? Please describe.**

I love how with jsr.io, Deno's std is on the way to become a true "standard library" for JavaScript. Not having to constantly search for (often abandoned) NPM packages for even the most basic stuff is huge. However, the fact that `@std/uuid` lacks a generator for v4 UUID (the most commonly generated one) is really annoying.

My team and I are developing a web app that needs to run on a company's intranet (HTTP on non-localhost address, therefore outside of secure context), so we cannot use `crypto.randomUUID` as recommended by the README.

**Describe the solution you'd like**

A "polyfill" implementation of `v4/generate` that falls back to `crypto.randomUUID` whenever it's available would be awesome.

**EDIT**: That's exactly what `npm:uuid` [already does](https://github.com/uuidjs/uuid/blob/main/src/v4.js).

**Describe alternatives you've considered**

Right now we are forced to use the `uuid` NPM package for a feature that IMO should be "built in", at least in the standard library.