Write utilities for SpatialData

[Artur-man]

Fixes#115.

This is a draft PR (from @kollo97) that introduces methods to write/update zarr stores, groups, atttibutes and SpatialElements:

• create zarr stores

v2	v3
✔	✔

• create zarr groups

v2	v3
✔	✔

• write zarr attributes

v2	v3
✔	✔

• create in-memory metadata

Ver.	image	label	shape	point	table
v2	✔	✔	✔	✔	✔
v3	✔	✔	✔	✔	❌

• create in-memory SpatialElements

Ver.	image	label	shape	point	table
v2	✔	✔	✔	✔	✔
v3	✔	✔	✔	✔	❌

• write metadata to json

Ver.	image	label	shape	point	table
v2	✔	✔	✔	✔	✔
v3	✔	✔	✔	✔	❌

• write SpatialElements
  https://spatialdata.scverse.org/en/latest/api/SpatialData.html#spatialdata.SpatialData.write_element

Ver.	image	label	shape	point	table
v2	✔	✔	✔	✔	✔
v3	✔	✔	✔	✔	❌

• write consolidated metadata: https://github.com/scverse/spatialdata/blob/ef88b5c9f9a7474051c47e20c1dcaa47f6842b83/src/spatialdata/_io/io_zarr.py#L320
• write SpatialData itself https://spatialdata.scverse.org/en/latest/api/SpatialData.html#spatialdata.SpatialData.write

v2	v3
✔	✔

• test on other example datasets from https://spatialdata.scverse.org/en/latest/tutorials/notebooks/datasets/README.html
• add to vignette and examples