Make anndata.utils.asarray part of public API

[jan-engelmann]

Please describe your wishes and possible alternatives to achieve the desired result.

Would it be possible to make asarray a public function?
I use it on a daily basis and we would like to rely on it for our package.
Are there any caveats or anticipated changes?

Thank you!

[flying-sheep]

related to this: scverse/scanpy#3386 (comment)

As a response to this thread about numba, @Intron7 had the idea to investigate and benchmark a little standalone “fast array utilities” library based on Rust (containing e.g. _mean_var).

I think this fits right in, as fast conversions between array types are very much in line with the scope of that package