Login & Signup enhancements

[vinaypuppal]

Describe the bug

1. No visual feedback like loader when logging in or signing up.
2. No validation of data or form fields on client-side or server-side. I can create users by submitting below details 😲
   
3. In the above screenshot, you can see the signup form has Login header.
4. Signing up should automatically login user which is better UX

To Reproduce
Steps to reproduce the behavior:

1. Go to log in or signup page
2. Try to create user
3. You can find above-listed issues or bugs

Expected Behaviour

1. Add a loader when the form is being submitted.
2. Add client-side form validation and also do same in serverside
3. Fix signup form header
4. On backend implement automatically login user when user signs up and reflect same on frontend side also

[vinaypuppal]

@pbteja1998 Please be cautious when adding external NPM packages i.e we should not bloat the app with some many dependencies which might increase bundle size which inturns affect user experience on slow devices and network conditions.

For example, instead of vue-overlay-loader, we can use loading and disabled prop on Button and also disable form fields while the form is getting submitted.

When adding any external dependency please make sure it's lightweight. You can check its impact on user devices here https://bundlephobia.com/