Implement conversion of Python array data -> Rust for upload/writing to Array

We currently have various support for reading Rust array data into Python (often zero-copy)

But we also need to fully implement the reverse conversions to make it easy to write Python data to Zarr stores

Start by tracing the existing support for reading Rust array data into Python and identify the corresponding conversion entry points for Python array data. Then follow the upload or writing path to an Array and determine how the conversion reaches Zarr stores. Done means reverse conversions are fully supported for writing Python data.

Written by the indexing model from the issue text.