Add optional depenency on hdf5plugin

[smsutherland]

Sometimes hdf5 compression plugins are in a non-standard directory which h5py can't find. In these cases it's useful to use hdf5plugin to ensure h5py is always able to open datasets with non-standard compression.
This PR adds an optional dependency on hdf5plugin for use in these situations.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (724ac50) to head (c92de8f).
⚠️ Report is 10 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main       #43   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           23        23           
  Lines         2494      2517   +23     
=========================================
+ Hits          2494      2517   +23     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[WillJRoper]

Some minor comments.

Main complaint by the CI workflows is that this causes a drop in unit test coverage. The new decortator needs some units tests added. By all means, use an AI assistant for them.

[smsutherland]

Also I just realized it might be worth it to check if hdf5plugin is installed, and only change the message if it isn't. If an OSError comes up while hdf5plugin is installed, it should go right through.

[WillJRoper]

Also I just realized it might be worth it to check if hdf5plugin is installed, and only change the message if it isn't. If an OSError comes up while hdf5plugin is installed, it should go right through.

Definitely, I did worry that it's going to catch a whole host of errors (though many will have triggered earlier than this).