Re-implement consolidated metadata in StoreToZarr

[cisaacstern]

As noted here

pangeo-forge-recipes/pangeo_forge_recipes/transforms.py

Lines 386 to 388 in 561897d

	# TODO
	# - consolidate coords
	# - consolidate metadata

consolidated metadata is not implemented in StoreToZarr. Here's the prior implementation:

pangeo-forge-recipes/pangeo_forge_recipes/recipes/xarray_zarr.py

Lines 694 to 697 in 3b3c13c

	if config.consolidate_zarr:
	logger.info("Consolidating Zarr metadata")
	target_mapper = config.storage_config.target.get_mapper()
	zarr.consolidate_metadata(target_mapper)

Like #556, this also depends on #564, so I'll address that first.

[cisaacstern]

xref leap-stc/ClimSim#38 (comment), the slow loading time there can probably be (entirely?) resolved by consolidated metadata.