Migrate USWDS to Node.js Module

[curt-mitch-census]

Currently the xd.gov codebase has the USWDS assets tracked in Github. This is fine for things like the custom stylings, but we shouldn't be tracking the minified JS, for example, as this makes updates harder to perform and these files are then treated as files we own and modify by Dependabot and other code-scanning services.

We should migrate the USWDS module to a current version of the Node.js module. We previously did this for the Bias Toolkit Frontend: XDgov/bias-toolkit-frontend#12.