[stable8] docs: Move more icons to outline

[backportbot]

Backport of #7862

Warning, This backport's changes differ from the original and might be incomplete ⚠️

Todo

• Review and resolve any conflicts
• Amend HEAD commit to remove the line stating to skip CI

---

Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.

[codecov]

Codecov Report

❌ Patch coverage is 16.66667% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 45.08%. Comparing base (f9b3a27) to head (c5ee4b7).
⚠️ Report is 14 commits behind head on stable8.

Files with missing lines	Patch %	Lines
src/components/NcListItem/NcListItem.vue	0.00%	3 Missing ⚠️
src/components/NcAppSidebar/NcAppSidebar.vue	0.00%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##           stable8    #7864   +/-   ##
========================================
  Coverage    45.08%   45.08%           
========================================
  Files          191      191           
  Lines         4749     4749           
  Branches      1169     1226   +57     
========================================
  Hits          2141     2141           
+ Misses        2514     2512    -2     
- Partials        94       96    +2     

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