Add a JS minifier Step

[pydsigner]

Right now we don't have any minifiers for JavaScript. minify-html comes with minify-js, but minify-js is known to have correctness issues: https://github.com/privatenumber/minification-benchmarks.

[pydsigner]

https://github.com/tdewolff/minify is built in Go but comes with Python bindings, but lacks wheels in its CI. Best play may be to make a pull request to add wheels, since the repository is actively maintained.

[pydsigner]

Another option could be to make PyO3 bindings to https://github.com/swc-project/swc; however, this project is much broader than our need, and could be a huge challenge to wrap for our needs.

[pydsigner]

See tdewolff/minify#599 and tdewolff/minify#600. Looks like Golang is very difficult to bind to Python, so may consider working on swc bindings with maturin.

[pydsigner]

SWC is about 10x slower than tdewolff-minify and produces about 1% smaller output.

[pydsigner]

We should be able to move forward with tdewolff-minify; though wheels won't be available for every platform, the most important by far will be covered along with several others. Mac users may need to use Docker or a VM as a workaround.