Is `ArrayV3Metadata` public API?

[TomNicholas]

In VirtualiZarr we now make pretty heavily use of some zarr-python internals, particularly ArrayV3Metadata, which is stored under one of the two main properties of a ManifestArray.

VirtualiZarr is a weird project and I don't expect us to be able to fully only use public zarr-python API (if anything we might want to go the other direction and get integrated upstream), but it would be good to know if you all consider ArrayV3Metadata a stable (semi-)public class or an internal implementation detail that could be removed at any time?

To be clear, the ship sailed on us using ArrayV3Metadata a while ago - it is too useful not to! I'm just raising this to track the question because @jhamman asked me to.

cc @maxrjones @abarciauskas-bgse

[d-v-b]

but it would be good to know if you all consider ArrayV3Metadata a stable (semi-)public class or an internal implementation detail that could be removed at any time?

I rate it extremely unlikely that we would remove the metadata classes. But I think those classes need some changes -- in particular, i think we should deprecate to_dict / from_dict in favor of to_json / from_json, and maybe a few other API changes might be warranted.