Add react-hot-toast pop-ups for each actions

[acecoder7]

I would like to add pop-ups using react-hot-toast for all successful or unsuccessful(error) actions like successful login/register, wrong email-password, successful file, URL upload and folder creation. This will enhance the user experience. Kindly assign this issue to me under GSSoC'23 so that I can make PR @srivastavaritik

here are the changes

• Improved css of signup page
• Added react-hot-toast pop-ups

Before-

After-

The messages for specific actions

[srivastavaritik]

Hi @acecoder7 , you can work on this.