[pgAdmin4][Patch]: RM_2596 - Query tool not working in DesktopRuntime on Mac OS X

Hi,

I inspect the react code and in call stacks, found `process.env.NODE_ENV` is undefined due to which 'SyntheticEvent.call' is not callable.

So, to fix this, i add 'definePlugin' to plugins for `dev` environment in `webpack.config.js`. Initially it was added only for `production` environment. but it is needed for both, because React code is conditional based on environment variables set.

Please find attached patch and review.

Thanks,

Surinder