(fix) The webpack hot reload server should wait for backend to get ready

[bbbneo333]

• When attempted to run npm run serve, the script opens up the url automatically on default browser of the dev machine
• When frontend build is finished, the page loads but with broken assets (open up network tab, there will be connection refused requests made by the browser).
• This happens because assets are actually served by the backend, and till it's not, it won't start listening to any incoming connections. Hence, the connection refused error.
• We need to find a way to delay thescript to emit frontend build till backend is ready.

[bbbneo333]

For ref, see - https://github.com/Sunny-Energy-AZ/sales-portal/commit/dc8674571cb65e4e9cd9cdb3b12808468c115d8d