feat: Implement ZEP 8 URL syntax support for zarr-python

[jhamman]

This PR implements support for the ZEP 8 URL syntax in Zarr Python.

Some examples of what now works:

import zarr

root = zarr.open_group('s3://bucket/data.zip|zip:|zarr3:')  # S3 → ZIP → Zarr v3
arr = zarr.create_array('memory:|zarr2:group/array', shape=(10, ), dtype='i4')  # Memory → Zarr v2

# custom adapter for icechunk
ds = xr.open_zarr('s3://icechunk-public-data/v1/glad|icechunk:')  # icechunk (from xarray)

TODO:

• Add unit tests and/or doctests in docstrings
• Add docstrings and API docs for any new/modified user-facing classes and functions
• New/modified features documented in docs/user-guide/*.rst
• Changes documented as a new file in changes/
• GitHub Actions have all passed
• Test coverage is 100% (Codecov passes)

closes #2943
fixes #2831
xref: zarr-developers/zeps#48

cc @jbms