Make _from_valid_data public

[vigji]

Is your feature request related to a problem? Please describe.

I would like to create valid datasets from the output of custom pipelines and not from file.

Describe the solution you'd like
I would simply make the movement.io._from_valid_data public - or add a public interface to it. Sorry if there's already one and I missed it!

[niksirbi]

Hey @vigji, we recently added a public from_numpy() function, I think this should cover your use-case?

You can try updating to the latest movement version to use that.

See our rationale in #194

[vigji]

Oh amazing exactly what I was looking for, thanks :)