Implement hot module reloading / React Fast Refresh

[pierre-dekode]

It seems that this is available in wp-scripts (see WordPress/gutenberg#28273) but it's not working with the Project Base current webpack config:

npm run start:hot

> start:hot
> wp-scripts start --hot

<i> [webpack-dev-server] Project is running at:
<i> [webpack-dev-server] Loopback: http://localhost:8887/, http://[::1]:8887/
<i> [webpack-dev-server] Content not from webpack is served from '/Users/pskli/Sites/avigo/app/public' directory
[webpack-cli] Error: Unique ports must be specified for each devServer option in your webpack configuration. Alternatively, run only 1 devServer config using the --config-name flag to specify your desired config.

It would be useful to be able to work on custom Gutenberg blocks without having a full page refresh — with code being injected into the open page instead.