[Demo] Move e-commerce demo from webpack to vite

[fzaninotto]

Problems

Create-React-App 5.0 has broken Hot Module Reloading, and the project looks abandoned. As a consequence, the developer experience with the demo is poor

Solution

Use Vite instead. This speeds up the development mode, solves the HMR problems, and doesn't slow down the build too much.

From make run-demo to loaded page in browser:

• master: 16s
• this branch: 11s

From make build-demo to generated files:

• master: 35s
• this branch: 40s

Closes #7826
Supersedes #7162

• Make the demo run fast in development mode
• Watch demo files and react-admin files
• Make sure that the demo works in a subdirectory (to publish at https://marmelab.com/react-admin-demo)
• do not mangle names
• enable profiling in production
• Update makefile to make the transition seamless for core developers

[WiXSL]

It works and it looks really fast!

✔️ Runs very fast
✔️ Hot reload works as expected
✔️ All scripts work

[slax57]

This will be a significant time save!