Support node names with string containing unicode code points..

[zoj613]

The Zarr V3 specification insists that node names must have a name, which is a string of unicode code points. It also recommends implementations to only use characters in the sets a-z, A-Z, 0-9, -, _, . , but doesn't enforce this. It also recommends using case-folded NFKC-normalized strings for non-ASCII unicode charecters. Ocaml seems to have a bunch of libraries to support this:

• Decoding utf-8 encoded strings with uutf
• Segmentation of unicode text with uuseg
• Normalization with uunf
• Inspection with uucp.

There is also an introductory text with usage tips that can help make things easy to implement.