Zarr v3 backend configuration

[alejoe91]

Depends on v3 port of:

• hdmf-zarr: Migrate hdmf-zarr from zarr-python v2 to v3 hdmf-dev/hdmf-zarr#325
• probeinterface: Support zarr v3 SpikeInterface/probeinterface#387
• spikeinterface: Support zarr v3 SpikeInterface/spikeinterface#4260

[h-mayorquin]

I took a first look, very high level:

1. The validator should check shard_shape against buffer_shape, not just chunk_shape. As far as I understand a shard is assembled whole in memory on every flush, so shard_shape sets a per-flush memory footprint a user can push until they run out of memory, and a shard bigger than the buffer also forces a read-modify-write since we write buffer by buffer. So I'd enforce shard_shape <= buffer_shape, ideally that it evenly tiles the buffer.
2. There's no user-facing documentation, we should do this and make this easy to review.
3. What do you think about defaults shard values? Should we write defaults equal bo the buffer size? non-shared by defaults?

@alejoe91 let me know if this is the type of feedback that you wanted or if I should look into other aspects of it.