[RFC]: add `@stdlib/iter/cartesian-power`

### Description

This RFC proposes adding the package `@stdlib/iter/cartesian-power`.

This package would be the iterator equivalent of [`@stdlib/array/cartesian-power`](https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/cartesian-power).

```javascript
function iterCartesianPower( x, n ) { ... }
```

where `x` is an input array-like object and `n` is an integer power.

Package: `@stdlib/iter/cartesian-power`
Alias: `iterCartesianPower`

### Related Issues

Related issues #1334.

### Questions

No.

### Other

No.

### Checklist

- [X] I have read and understood the [Code of Conduct](https://github.com/stdlib-js/stdlib/blob/develop/CODE_OF_CONDUCT.md).
- [X] Searched for existing issues and pull requests.
- [X] The issue name begins with `RFC:`.