Provide default options for chunking of datasets (issue #635)

[ehennestad]

Fix #635

Motivation

Provide better chunking options for files in cloud storage

How to test the behavior?

To be determined

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?

[ehennestad]

Some open questions:

• Should each possible property / dataset name be present in the configuration (chunk_params.json)? Or should there be one default that applies to all datasets, and overwrites would happen on specific datasets?
• Should each dataset be a candidate for chunking, or only datasets like "data", "timestamps". Any others?
• Should chunking be specified for datasets that are smaller than the chunk size? I.e chunkSize == maxSize?
• Should chunk_dimensions be specified for each set of dimension options, similar to how it is done in the nwb schema?

I.e. https://github.com/NeurodataWithoutBorders/nwb-schema/blob/473fcc41e871288767cfb37d83315cca7469b9d1/core/nwb.base.yaml#L100-L110

dims:
    - - num_times
    - - num_times
      - num_DIM2
    - - num_times
      - num_DIM2
      - num_DIM3
    - - num_times
      - num_DIM2
      - num_DIM3
      - num_DIM4

@bendichter