assistant: Change the quote selection crease icon (#16180)

Felt like this icon was more fitting to the idea of selected text, and looked less like a document.

Release Notes:

- N/A

assets/icons/text_select.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-text-select"><path d="M5 3a2 2 0 0 0-2 2"/><path d="M19 3a2 2 0 0 1 2 2"/><path d="M21 19a2 2 0 0 1-2 2"/><path d="M5 21a2 2 0 0 1-2-2"/><path d="M9 3h1"/><path d="M9 21h1"/><path d="M14 3h1"/><path d="M14 21h1"/><path d="M3 9v1"/><path d="M21 9v1"/><path d="M3 14v1"/><path d="M21 14v1"/><line x1="7" x2="15" y1="8" y2="8"/><line x1="7" x2="17" y1="12" y2="12"/><line x1="7" x2="13" y1="16" y2="16"/></svg>

crates/assistant/src/assistant_panel.rs

@@ -4470,7 +4470,7 @@ fn quote_selection_fold_placeholder(title: String, editor: WeakView<Editor>) ->
                 ButtonLike::new(fold_id)
                     .style(ButtonStyle::Filled)
                     .layer(ElevationIndex::ElevatedSurface)
-                    .child(Icon::new(IconName::FileText))
+                    .child(Icon::new(IconName::TextSelect))
                     .child(Label::new(title.clone()).single_line())
                     .on_click(move |_, cx| {
                         editor

crates/ui/src/components/icon.rs

@@ -254,6 +254,7 @@ pub enum IconName {
     Tab,
     Terminal,
     TextCursor,
+    TextSelect,
     Trash,
     TriangleRight,
     Undo,
@@ -417,6 +418,7 @@ impl IconName {
             IconName::Tab => "icons/tab.svg",
             IconName::Terminal => "icons/terminal.svg",
             IconName::TextCursor => "icons/text-cursor.svg",
+            IconName::TextSelect => "icons/text_select.svg",
             IconName::Trash => "icons/trash.svg",
             IconName::TriangleRight => "icons/triangle_right.svg",
             IconName::Update => "icons/update.svg",