Update folder selection logic to handle deep folders.

Summary

Removes constant for max options per section, replaces with dynamic value calculated in the ResourceSelection component
Moves all 'can select' logic into the ResourceSelection component
Adds function to allow determination of select all indeterminate state
Updates select all showing, based on whether selecting every displayed node could be added and still result in fewer than or equal to the total max number of question options.
Update select all toggling to reuse existing toggleSelect function for consistency
Update toggleSelect function to fetch additional data from the backend in case it is not annotated onto the topic (the case when the exercises are not direct children or in the first 12 children of the topic)
Update showing the number of questions warning to be purely based on whether we're showing select all, if not, we show the message to explain why one or more items are not selectable
Fix indeterminate state display for folders

Change to behaviour for clarity:

Update to always show checkboxes for folder and resources
Instead, disable checkboxes when the folder or resource cannot be selected
Do not disable checkboxes if the item is currently selected
Without this change, an indeterminately selected folder cannot be selected/deselected

Point for reflection: I tried to make it so that if a folder was indeterminately selected it and selecting it would exceed the max questions, it would deselect instead - this all worked, except that the KCheckbox did not properly update to the unselected state, so it made the UI more confusing. Instead, it retains its default behaviour, and instead displays the warning that too many questions are now selected.

Change to behaviour that can be reverted:

I updated the max questions option per section to be dynamic based on how many questions you were trying to choose, so if you were trying to choose 5 questions to add to your quiz, you could only select a total of 50 questions. I can revert this, but it seemed a little bit sensible?

References

Fixes #12327

Reviewer guidance

Select, deselect, select all, unselect all, select some resources in a folder, and navigate to the parent. Just do all the permutations of selecting and deselecting and make sure weird edge cases don't arise.

In spite of the disabled checkboxes, it is still possible to get into a state where you have too many resources selected, but the number of paths to get there is much smaller.

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

Asset type	Download link
PEX file	kolibri-.pex
Windows Installer (EXE)	kolibri-0.17.0a0.dev0+git.167.g9a42970a-windows-setup-unsigned.exe
Debian Package	kolibri_0.17.0a0.dev0+git.167.g9a42970a-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.17.0a0.dev0+git.167.g9a42970a-0.4.2.dmg
Android Package (APK)	kolibri-0.17.0a0.dev0+git.167.g9a42970a-0.1.3-debug.apk
TAR file	kolibri-0.17.0a0.dev0+git.167.g9a42970a.tar.gz
WHL file	kolibri-0.17.0a0.dev0+git.167.g9a42970a-py2.py3-none-any.whl

learningequality / kolibri