Follow-up to #2405057: Replace arrow-asc and arrow-desc images with Libricons and implement using CSS
Replace these icons with the Libricon SVGs:
* menu-collapsed-rtl.png
* menu-collapsed.png
* menu-expanded.png
* menu-leaf.png
See: #1356602: [META] Clean up icons in misc
Remaining tasks
* Review/screenshots in stark.
Beta phase evaluation
| Issue category | Task because it's code cleanup |
|---|---|
| Unfrozen changes | Unfrozen because it only changes HTML/CSS |