Allow redirect URL to be set via conditions

[engram-design]

There's some cases where more control over the logic of redirection is required. For instance, you might want to redirect to URL A if Field A, Field B, and Field C equal a value, and URL B is Field A and Field C equal another value.

We would introduce another option for "Conditional URL", which would either allow you to just use Twig to determine your logic, or a conditions builder similar to fields, where you define your URLs and for each, define the logic.