project_search: Add button to collapse/expand all excerpts (#41654)

<img width="500" height="834" alt="Screenshot 2025-11-03 at 12  59@2x"
src="https://github.com/user-attachments/assets/15c5e1fc-2291-41b4-9eec-a8cfa5a446c7"
/>

Releases Note:

- Added a button that allows to expand/collapse all project search
excerpts at once.

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Co-authored-by: Danilo Leal <daniloleal09@gmail.com>

crates/icons/src/icons.rs

@@ -53,6 +53,7 @@ pub enum IconName {
     Check,
     CheckDouble,
     ChevronDown,
+    ChevronDownUp,
     ChevronLeft,
     ChevronRight,
     ChevronUp,