Upgrade and tweak scss compliation

[l3aconator]

Context: When building the marketing site, our build tool fires off tons of deprecation notices per the following article: https://sass-lang.com/documentation/breaking-changes/slash-div

• Remove node-sass for latest sass
  • Node Sass and libsass are deprecated: https://sass-lang.com/blog/libsass-is-deprecated
    The preferred package to use now is dart-sass (sass).
• Upgrade sass-loader to 10.2.0 <- this is the latest version we can go to given storybook
  • This was necessary to pick up the updated scss syntax
• Run migration tool on the deprecated scss syntax
• Upgrade gulp-sass

This PR needs a good amount of scrutiny and I will need help releasing to npm.

[saralohr]

This looks good to me! Happy to help with NPM deploy or we can get you added if you'd rather self-serve.

[bradjteamsnap]

looks good to me as well, tried building the brach locally just to be sure 👍

[l3aconator]

@saralohr I would love your help with the NPM deploy whenever you get a chance :)

[saralohr]

Sure @l3aconator I'll merge this and deploy to NPM.