[Feature] Conditional `d_features`

[markoshorro]

Maybe we want to limit certain values to the value of other variables, e.g.:

d_features:
    foo:
        evaluate: True
        type: "string"
        value: [0,2]
    bar:
        evaluate: True
        type: "string"
        value: [0,1]

For the sake of the argument, imagine when foo is lower than 2, bar variable has no effect and, therefore, we do not want to generate the combination with the bar values. So the list of combinations would be:

• [foo: 0] , [foo: 2, bar: 0], [foo: 2, bar: 1]

We could write that description as:

    bar:
        evaluate: True
        type: "string"
        value: [0,1]
        restrict: "foo > 1"

[markoshorro]

I had to rewrite the product, inspect the values, and discard those which I do not want. This is not fast at all... But it gives a lot of functionality.