Consider conda-package-streaming for inspect_package.conda

[mbargull]

As of version 1.11, binstar_client.inspect_package.conda.inspect_conda_info_dir uses a temporary directory to extract the package metadata.
With conda-package-streaming, we could directly read those data from a stream and avoid the need for tempfile.

At conda-forge we experienced upload failures on Windows (CI on Azure) after updating anaconda-client from 1.8 to 1.11.
This could be tracked down to a permission error whilst inspect_conda_info_dir tried to clean up its tmpdir.
Now, the (yet to be determined) culprit is of course not with anaconda-client but with whatever broke the %TEMP% access.
(For now, we are considering to simply work around it by setting %TEMP% to another path; ref: conda-forge/conda-smithy#1699 .)

But, since conda-package-streaming is already "at hand", it would make sense to use it.

[mbargull]

cc @dholth 'cause conda-package-handling/streaming ;)

[dholth]

Would be very similar to what standalone conda-index does.