Use middleware to add nonce and CSP headers

[hursey013]

Changes proposed in this pull request:

• Refactors middleware to allow chaining of multiple middlewares
• Refactors Next/Image to remove inline styles
• Add CSP headers and nonce via middleware

Related issues

https://www.58bits.com/blog/chaining-or-combining-nextjs-middleware
https://nextjs.org/docs/app/building-your-application/configuring/content-security-policy
https://github.com/vercel/next.js/tree/canary/examples/with-strict-csp
vercel/next.js#45184

Submitter checklist

• Added logging is not capturing sensitive data and is set to an appropriate level (DEBUG vs INFO etc)
• Updated relevant documentation (README, ADRs, explainers, diagrams)

Security considerations

None

[echappen]

Thanks for all of this work, Brian, I really like the separation of concerns this approach takes. There are some concepts which I'd like to better understand before I approve. LMK if a chat would be better.