Allow plugins to be enabled, disabled, and applied via env vars.

[rtibbles]

Summary

• Adds environment variables to allow applying, enabling, and disabling plugins via a comma separated list of plugin names.

References

No actual issue for this, but has something that has come up a few times to make deployment for BCK easier, and also for enabling plugins for use in our Kolibri Apps.

Reviewer guidance

Test out each of the new environment variables.

I also thought I saw an issue where the environment variable set enabled plugins got saved to the plugin configuration when a Kolibri upgrade occurred - but I wasn't able to replicate on further testing.

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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

• 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-0.18.0.dev0_git.20241114175825.pex
Windows Installer (EXE)	kolibri-0.18.0.dev0+git.20241114175825-windows-setup-unsigned.exe
Debian Package	kolibri_0.18.0.dev0+git.20241114175825-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.18.0.dev0+git.20241114175825.dmg
Android Package (APK)	kolibri-0.18.0.dev0+git.20241114175825-0.1.4-debug.apk
TAR file	kolibri-0.18.0.dev0+git.20241114175825.tar.gz
WHL file	kolibri-0.18.0.dev0+git.20241114175825-py2.py3-none-any.whl

[marcellamaki]

code read through makes sense, and a fair number of permutations of manual QA indicate this is working as expected