[BUG] Validation in Company Signup Request

[itsGyanendra]

Describe the bug
Sometimes, many HR personnel register multiple times, making it necessary to manually cross-validate with the company's master database.

Expected behavior
If the email entered by the HR has already been authenticated, an error should be displayed during the sign-up process. They should then be given the option to reset their password if they do not remember it, or to proceed to the login page.
If the email entered by the HR has already been pending for verifier to verify, an error should be displayed during the sign-up process. They should then be given the option to contact Placement coordinators to verify their request