Add Ome-Zarr datasets

[normanrz]

The webknossos-libs feature the fantastic Dataset-API upon all of the wkcuber features and others build. Since, we want to support Ome-Zarr in the webKnossos ecosystem, I think it would be very handy to have a OmeDataset class. Ideally, the Ome implementation would be a drop-in replacement for Dataset. Instead of datasource-properties.json it would read/write a OME-NGFF metadata and Zarr instead of WKW.

Plan to implement:

• Add Zarr storage backend Add Zarr backend for Dataset #622
• Allow cloud-storage for Zarr Add cloud-storage support to Zarr for Datasets #651
• wkcuber support of Zarr Enable use of Zarr datasets in wkcuber #654
• Support OME-Zarr metadata (replacing datasource-properties.json)

Followups

• Enable more compression methods for Zarr datasets Enable more compression methods for Zarr datasets #652
• Enable sharding of Zarr datasets Enable sharding for Zarr datasets #653 (see Add Sharding Support zarr-developers/zarr-python#877)