Feature request: Save YAXArray or Dataset into a Zarr group

Multiple Datasets in the Common Data Model V4 can be stored in the same file.
Hereby, they are organized in (nested) groups, analog to files in directories and subdirectories.

For example, xarray.Dataset.to_zarr has the option group to specify the path inside the zarr storage in which the dataset should be stored.
Similarily, zarr.hierarchy.group has the option path to specify the (group) path. The prototype (and part of xarray roadmap) xarray-datatree uses this to represent a tree of Datasets as its own type. I think it is already implemented in Zarr.jl function Zarr.zcreate in option name.

This is of particular importance when it comes to store data cubes of different spatio-temporal resolutions in the same store. I'd be great to have an additional group option to the function savedataset and savecube.

Start by locating the savedataset and savecube entry points and reading how they currently write Zarr storage. Trace the existing storage path and determine how a group option should map to nested groups; done means both functions can save into the requested group without changing other output behavior.