Add in submit quiz button for non-large screen sizes.

[rtibbles]

Summary

• Adds the submit button back for non-large screen sizes
• Deliberately does not include the number of questions answered as it takes up too much space
• Fixes unreported bug in section change handling on tablet and phone screen sizes
• Updates ExamPage KSelects to be annotated with answer state, parallel to the accordion display.

References

Fixes #12410

Reviewer guidance

View on a tablet or phone screen dimensions.
Ensure that the submit quiz button shows up as a flat button, then a raised one once all questions are answered.
Ensure that it comes last in the tab order after the previous/next buttons
Ensure that changing the section via the top KSelect works.

Mobile

Tablet

Desktop

(screenshots taken prior to addition of answer state indicators in KSelect)

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-.pex
Windows Installer (EXE)	kolibri-0.17.0a0.dev0+git.238.ga3c24190-windows-setup-unsigned.exe
Debian Package	kolibri_0.17.0a0.dev0+git.238.ga3c24190-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.17.0a0.dev0+git.238.ga3c24190-0.4.2.dmg
Android Package (APK)	kolibri-0.17.0a0.dev0+git.238.ga3c24190-0.1.3-debug.apk
TAR file	kolibri-0.17.0a0.dev0+git.238.ga3c24190.tar.gz
WHL file	kolibri-0.17.0a0.dev0+git.238.ga3c24190-py2.py3-none-any.whl

[marcellamaki]

looks good - all manual QA checks out including indicator