Add subclass for decompressed arrays

Following [this comment](https://github.com/data-apis/array-api/discussions/968#discussioncomment-14350012), add a thinly wrapped native Blosc2 class for decompressed arrays, which are currently just plain NumPy arrays. Would have to support certain additional operations and comparisons (``==``, ``__array_namespace__()``), but it will inherit most of the useful machinery directly from NumPy.

Would have to change ``np.empty`` references for loading slices etc. from C functions in the code base, possibly some other things.