[core] Default to application/octet-stream content type for multipart blobs

Packages impacted by this PR

@azure/core-rest-pipeline

Issues associated with this PR

Fixes #28081

Describe the problem that is addressed by this PR
According to the multipart/form-data specification, binary content should have a default Content-Type of application/octet-stream if none is provided. Not supplying a Content-Type value implies that the content is text-based with a default encoding.
This PR corrects behavior so that multipart fields with values of type Blob and File have their content type set to application/octet-stream in the multipart request if no other content type is specified.
Are there test cases added in this PR? (If not, why?)
Fixed existing test to conform to corrected behavior.

API change check
API changes are not detected in this pull request.


Made most documentation build and added examples

This replaces my previous PR https://github.com/PyAbel/PyAbel/pull/75.
I did a few things here:

I added a line to conf.py to allow Sphinx to find the pyabel packages. This was necessary for the documentation to build on my system.

I removed all of the MOCK_MODULES in doc/conf.py since readthedocs.org now supports numpy, scipy, and matplotlib, and using these packages is required for the plot_directive to make the images for the examples.

As discussed in Issue https://github.com/PyAbel/PyAbel/issues/77 I included the examples in the documentation by adding a few .rst files to the doc directory. This may not be the way that we ultimately want to include the examples, but it's a nice demonstration of roughly how to it. You can see them here: http://pyabel-dh-fork.readthedocs.org/en/latest/example_hansenlaw_Xe.html

As discussed in Issue https://github.com/PyAbel/PyAbel/issues/74, I added

from . import basex
from . import benchmark
from . import direct
from . import hansenlaw
from . import three_point
from . import tools

to abel.__init__.py so that all of the submodules can be imported.
I think that this is good to merge. Can @stggh, @rth, and @DhrubajyotiDas check briefly to make sure that I have not made anything terrible happen. I changed a few other scattered things that were casing problems with the docs.

Looks good to me. Great work @DanHickstein!

Okay, I'll merge this one too. Huzzah!


Change references from older interface to this one

e.g. https://code.kx.com/q/interfaces/csharp-client-for-q/ points to old location

Created docs issue https://github.com/KxSystems/docs/issues/39