Implement missing X509 extensions and corresponding tests

[JonSnowWhite]

Problem

Currently, X509-Attacker implements the BasicConstraint and KeyUsage extensions. Some are still missing and their corresponding tests in X509-Anvil are not implemented.

Task

Implement the missing extensions in X509-Attacker and re-implement the tests in X509-Anvil. The re-implementation will be easy once the extensions are implemented in X509-Attacker.