Signup js adjusted for a better error handling logic

[gbengaoluwadahunsi]

Summary This pull request (PR) enhances the error handling of the sign-up JavaScript (JS) functionality

Motivation The motivation behind this PR is to improve the robustness and reliability of the sign-up feature by enhancing its error handling.

Testing The PR has been thoroughly tested beyond the automatic hooks. The Jest test function file systematically validates the behavior of the sign-up JS file under different conditions, including both normal operation and error scenarios. This comprehensive testing approach helps to ensure that the sign-up functionality behaves as expected and handles errors gracefully.