Add new python file

Summary by Bito

This pull request updates the 'sample.py' file in a Flask web application with intentional security vulnerabilities for educational purposes. It changes the form field name for retrieving the password from 'password' to 'pass', likely as part of a broader security enhancement initiative. The PR also introduces a Go file 'user.go' implementing a secure web application using the Gin framework, showcasing secure coding practices.

Unit tests added: False

Estimated effort to review (1-5, lower is better): 1