Enable https reduction (off NGINX server only) and auto-detect storage_type

[valeriupredoi]

Description

Yet another contribution towards #231

• introduce a utility that should be able to detect storage type, and enable the user not to be forced to specify the storage_type kwarg in Active
• allow for files and datasets from files on https servers to be handled, with the caveat that reductions happen inside the PyAS client, and not yet delegated to Reductionist

Reduction inside PyAS client is obviously slower than if delegated to Reductionist, but it's still a good exercise, and it scales very well (ie 2x data = 2x time)

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• ☝ Create an issue to discuss what you are going to do

Checklist

• This pull request has a descriptive title and labels
• This pull request has a minimal description (most was discussed in the issue, but a two-liner description is still desirable)
• Unit tests have been added (if codecov test fails)
• All tests pass

[valeriupredoi]

@bnlawrence this is the bit I was on about on the call

[bnlawrence]

That's great. I think we'd need to put the response to that in the json going to reductionist, rather than in the URI itself.