Update to SAFE v5

[jwthomson]

Mostly I followed the official instructions to do the update (https://safe-stack.github.io/docs/recipes/upgrading/v4-to-v5/).

The main deviations were:

• Not adding Tailwind, since the whole thing is using Bulma.
• Not upgrading tests since there are no tests
• Change the server port to 8085 to align with the Vite config
• Add a reference to App.js to index.html - I didn't investigate how it was hooked in before but this resolved it being a distinctly un-reactive react app.

I also updated the solution branch: #176

[Larocceau]

@jwthomson reviewed and made changes. If you review my commits we can merge