Implement unit tests for aivpn.py modules

[ay-bh]

Is your feature request related to a problem? Please describe.
The AI VPN project currently lacks a comprehensive suite of unit tests.

Describe the solution you'd like
I propose the addition of these unit tests for aivpn.py that covers critical paths and edge cases for the validate_identity and manage_whois functions. These tests should mock external dependencies, like the Redis database, to ensure we're accurately isolating and testing the logic contained within each function.

The unit tests should:

• Validate correct handling of valid and invalid identities.
• Ensure the manage_whois function correctly interacts with the mocked Redis database and returns the expected outputs.
• Verify error handling and edge cases, such as non-existent users or database connection issues.