Upgrade Webpack to version 5

[jenshnielsen]

To do this it required setting production path as in ipympl and change the webpack cli from -p to --mode=production which should be indentical.

I have manually tested that a local build of the notebook extension still works as expected.

Note that since this does an npm update the changes to package-lock.json are significant. It could be worthwile updating the package lock file independently before this pr.

closes #224

[github-actions[bot]]

:point_left: Launch a binder notebook on branch jenshnielsen/ipycytoscape/webpack5

[jenshnielsen]

Thanks, just trying to land small things that I find I as I familarilze my self with the codebase and how the ts/js/python stuff is integrated. Was experimenting to see if updating javascript packages would change any thing