[Task] Write unit tests for password salting and hashing

[abi-sheks]

• Write unit tests that check the following:
  1. Passwords are successfully salted and hashed.
  2. Salting ensures that the same password generates different hash values on each test run.
  3. The system should correctly verify a password against its hash.
  4. Ensure that the password hash is not retrievable from the hash itself.
  5. Test for edge cases, such as very short or very long passwords.