Nested IP whitelist

[danielburger1337]

Description

This PR introduces support for array values in the scheb_two_factor.ip_whitelist configuration option. This allows the user to specify the new-ish IpUtils::PRIVATE_SUBNETS constant together with some public IPs.

scheb_two_factor:
    # This already worked
    ip_whitelist: !php/const Symfony\Component\HttpFoundation\IpUtils::PRIVATE_SUBNETS

Now this works as well:

scheb_two_factor:
    ip_whitelist:
        - 9.9.9.9
        - [1.1.1.1, 1.0.0.1] 
        - !php/const Symfony\Component\HttpFoundation\IpUtils::PRIVATE_SUBNETS

[scheb]

Thanks for contributing once again! 🙇

Released as v7.2.0