Define parser-specific Store protocols using obspec primitives

[maxrjones]

Previously, VirtualiZarr imported ReadableStore from obspec_utils.protocols, which was overly broad relative to the methods used by parsers. This PR updates the parsers to directly define their required protocols using obspec.

As a consequence, obspec is added as a direct dependency (rather than via obspec_utils). I have also bumped the minimum obspec_utils version due to the ParallelStoreBug in v0.7.0 referenced in #858.

• Closes #xxxx
• Tests added
• Tests passing
• Full type hint coverage
• Changes are documented in docs/releases.rst
• New functions/methods are listed in api.rst
• New functionality has documentation

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.97%. Comparing base (052f7d1) to head (99f2fb3).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #859      +/-   ##
==========================================
- Coverage   88.99%   88.97%   -0.03%     
==========================================
  Files          34       34              
  Lines        1945     1959      +14     
==========================================
+ Hits         1731     1743      +12     
- Misses        214      216       +2     

Files with missing lines	Coverage Δ
virtualizarr/parsers/dmrpp.py	83.62% <100.00%> (+0.29%)	⬆️
virtualizarr/parsers/hdf/hdf.py	95.65% <100.00%> (+0.12%)	⬆️
virtualizarr/parsers/kerchunk/json.py	100.00% <100.00%> (ø)
virtualizarr/parsers/typing.py	100.00% <100.00%> (ø)
virtualizarr/parsers/zarr.py	97.54% <100.00%> (-1.21%)	⬇️

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