Fix security warnings and update dependency versions

[gary-archer]

• Update to Node.js 22
• Update dependencies to fix security warnings
• Minor webpack changes to copy HTML / CSS to the dist folder after every edit to make SPA deployment and development cleaner
• Add bootstrap CSS to the repo rather than complicate the CSP

I am also going to remove Cypress tests from this repo.
Cypress adds a lot of maintenance overhead, that adds unwanted noise and maintenance overhead to this repo.
However, before merging I will create a 'Cypress' branch with the previous code, so that we have a backup.