Performance improvements to scangov site

[aaronhans]

Is your feature request related to a problem? Please describe.

The scangov site is well done but currently gets a low performance score in a lighthouse audit. We should make this better before we add performance grading of other sites to the system.

Describe the solution you'd like

The choice to use static site generation is an excellent one. I think a big step towards fixing this issue would be to lean more heavily into the static site generation aspect. This would also help with SEO because Google indexes server rendered content much more quickly than client side rendered content. I would add a dynamic data layer that pulls all the reports from the scangov-auditor S3 bucket at build time and creates all the pages using the static site generator so there is less client side page creation at render time. Then look into all the other enhancements usually identified by lighthouse like ripping out all the pieces of bootstrap not being used by doing dynamic css pruning and stuff like that.

Additional context

This should be done independent of any design changes, just rebuild the site a little differently so it is faster and we can then start publishing all the data about everybody else's performance.

[lukefretwell]

@aaronhans my technical limitations (ie Bootstrap) are being exposed! 😆