Reduce whl size, bundle C extensions for all Python 3 versions on Windows

[rtibbles]

Summary

• Removes the duplication of dependencies for abi3 compatible bundles (i.e. cryptography)
• Instead, if we are on an abi3 compatible Python version (see https://docs.python.org/3/c-api/stable.html#limited-c-api), and we have bundled platform and machine architecture dependencies for it, we add the relevant folder to the sys.path

References

Resolves build failure caused by an overly large wheel file

Reviewer guidance

Verify that the built WHL file is less than our 100MB limit.
Install the WHL file into a clean Python 3.6+ virtual environment
Run kolibri shell
Verify that import cryptography does not produce an ImportError

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Testing checklist

• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical user journeys are covered by Gherkin stories
• Critical and brittle code paths are covered by unit tests

PR process

• PR has the correct target branch and milestone
• PR has 'needs review' or 'work-in-progress' label
• If PR is ready for review, a reviewer has been added. (Don't use 'Assignees')
• If this is an important user-facing change, PR or related issue has a 'changelog' label
• If this includes an internal dependency change, a link to the diff is provided

Reviewer checklist

• Automated test coverage is satisfactory
• PR is fully functional
• PR has been tested for accessibility regressions
• External dependency files were updated if necessary (yarn and pip)
• Documentation is updated
• Contributor is in AUTHORS.md

[github-actions]

Build Artifacts

Asset type	Download link
PEX file	kolibri-0.16.0b10.dev0_git.9.g08826ad2.pex
Windows Installer (EXE)	kolibri-0.16.0b10.dev0+git.9.g08826ad2-unsigned.exe
Debian Package	kolibri_0.16.0b10.dev0+git.9.g08826ad2-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.16.0b10.dev0+git.9.g08826ad2-0.3.0.dmg
Android Package (APK)	kolibri-0.16.0b10.dev0+git.9.g08826ad2-0.1.0-debug.apk
TAR file	kolibri-0.16.0b10.dev0+git.9.g08826ad2.tar.gz
WHL file	kolibri-0.16.0b10.dev0+git.9.g08826ad2-py2.py3-none-any.whl

[jredrejo]

Code looks fine and tested as the description says without any issue.