ManifestArrays and ChunkManifests should have the same shape for scalars

[maxrjones]

Kerchunk parsers (e.g., NetCDF3) are returning 1 dimensional arrays for scalar arrays, but we should enforce consistency between the shape of ManifestArrays and ChunkManifests for scalar arrays.

Pulling this fix out of #769 to be addressed in a separate PR - https://github.com/maxrjones/VirtualiZarr/blob/2433372006a385cb6cd4a34f407c2643f46c6232/virtualizarr/manifests/store.py#L182-L184

[TomNicholas]

Is this the same thing as #729?

[maxrjones]

Is this the same thing as #729?

yeah thanks for linking to that PR, that'll definitely help. There's probably also a change required in https://github.com/zarr-developers/VirtualiZarr/blob/main/virtualizarr/parsers/kerchunk/translator.py to fix the shape of ChunkManifest._paths, etc for scalars.