[Zarr-Support] Add Zarr v2 reader support

[ehennestad]

Motivation

This PR adds a Zarr v2 reader implementation for nwbRead.

Depends on: https://github.com/ehennestad/MATLAB-support-for-Zarr-files/tree/phase7-compound-dataset-support

How to test the behavior?

nwbtest('Name', 'tests.unit.io.backend.*')

Checklist

• Have you ensured the PR description clearly describes the problem and solutions?
• Have you checked to ensure that there aren't other open or previously closed Pull Requests for the same change?
• If this PR fixes an issue, is the first line of the PR description fix #XX where XX is the issue number?

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