Function to compute the matrix power of order k

It can possibly be implemented like so:

```julia
pow(M::IntervalMatrix, k; algorithm=...) = get(IntervalMatrixPower(M, k; algorithm=...))
```

_Originally posted by @mforets in https://github.com/_render_node/MDIzOlB1bGxSZXF1ZXN0UmV2aWV3VGhyZWFkMjMzNjI2MjczOnYy/pull_request_review_threads/discussion_