Solve performance issues

[BlueSlug]

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

Performance of the site is slow, as measured by Lighthouse in the Chrome DevTools. This is likely resulting in reduced consumption and access of the site.

The performance of the build action should also be reviewed as part of this work.

Describe the solution you'd like

Aspects which could be explored in order to improve performance:

• look into UIO issues
• enable compression
• The service worker could potentially be running every time the site loads. Try running Lighthouse action without service worker enabled.
• SVG assets are loaded individually, creating unnecessary overhead. These could be combined into a single image and used as a sprite (see Compile image assets into single sprite file #808)
• minifying JS and CSS files to reduce transfer times

Describe alternatives you've considered

See above for a list of suggestions

Additional context

A performance report from running the site locally on a fast computer. Attempts to run performance auditing on the live site did not finish after several hours.