Implement URI scheme for command-line (and SDK) IO

[nicholasjng]

We would like to support benchmark result IO to various places without having to prepare complex logic on the command line directly.

For example, an invocation like nnbench benchmarks.py -o gs://my-bucket/my-result1.json should write the results to json on disk, and then send the file to the given GCS bucket. A tested solution for this is the fsspec project.

The same works for an existing record upload, where nnbench benchmarks.py -o bq://my-proj/my-dataset/my-table could push the results into the given BQ table.

The interesting case is record fetching from databases in evaluation / comparison scenarios. For example, when comparing a local run (say 1.json) to latest results in BQ where a context value foo equals 'bar', it would be nnbench compare 1.json bq://my-proj/my-dataset/my-table, but WHERE context.foo='bar'.

This could be supported with a command-line parameter --query.

Urgent for building a comparison pipeline.