Provide docker script for easy local testing

[ryanking13]

Often, the most annoying part of testing the packages is installing the browser runtime and web drivers, I think we can reuse the pyodide-env docker image to provide a way to run local testing easily.

It can be used for building packages as well, but I want to use it for testing only, as building packages require different tools per package but testing requires always the same thing.

Ideally, we can create a new base Docker image optimized for testing, but we can also start reusing the existing pyodide-env image.

[daram62]

I'd like to work on this issue. Could you please assign it to me?

[ryanking13]

@daram62 Sure, assigned to you!