Feature: OrderedListInterface#combine

[boesing]

For native PHP arrays, there is a array_combine function which combines the values of two arrays to a map where all values from the first array are used as keys and all values of the 2nd array are used values.

Obviously, both arrays have to have the same size. The value which is passed to OrderedListInterface#combine should represent the keys while the OrderedListInterface itself can be used as values.

/**
 * @template TValue
 */
interface OrderedListInterface
{
    /** 
     * @template T of array-key
     * @param OrderedListInterface<T> $keys 
     * @return MapInterface<T,TValue>
    public function combine(OrderedListInterface $keys): MapInterface;
}