Design alignment updates

[marcellamaki]

Summary

Handles various pieces of design speccing alignment feedback, including some tasks in #8563 and other PR feedback and issues.

Included Items

Topics Page

• Add "active" styles for folders and search tab
• Active side panel buttons styles

Library page

• Fix mobile card view that sometimes shows up as a grid with toggle, when should just be single card
• no toggle on 0 results (in case there are ever a 0 results page)

• Active side panel buttons styles

view 1	view 2

Bookmarks page

• Card: Add text truncation to manage long description overflow and spacing issues

Reference

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

[rtibbles]

Let's merge this - but I think we can do some more cleanup here.

[rtibbles]

Should do this as a computed prop - and there's probably a better way to do the existence check.