Testing Site URL: https://gh-imp-2021-02122.castlecraft.co.in
Pull Request URL: https://github.com/frappe/frappe/pull/15200
Pull Request Title: feat: Country and Age during Signup
Pull Request Description: **Asking Country and Verifying Age during Signup:**
- This can be enabled from Website Settings.
- Once enabled, the signup form will have these fields additionally.
- Based on the user’s input, values will be stored in User doctype.
Steps to test:
- From website settings, enable Show Country dropdown during Signup and Verify Age during Signup. Save.
- Go to the Signup form. Fill in the details and signup.
- Try the signup form with the settings disabled.