Implement set.difference()

Compares first iterable against one or more other iterables and iterates the values in array that are not present in any of the other arrays.

```
function *difference<T>(
    ...iterables: Array<Iterable<T> | Iterator<T>>
): Iterable<T>
```

Needs to be implemented:
* `summary.difference()`
* `summary.differenceAsync()`
* `Stream.difference()`
* `AsyncStream.difference()`
