Show error and warning indicators in project panel items (#18182)

Closes #5016

Release Notes:

- Add setting to display error and warning indicators in project panel
items.


https://github.com/user-attachments/assets/8f8031e6-ca47-42bf-a7eb-718eb1067f36

---------

Co-authored-by: Thorsten Ball <mrnugget@gmail.com>
Co-authored-by: Danilo Leal <67129314+danilo-leal@users.noreply.github.com>

crates/ui/src/components/icon.rs

@@ -277,6 +277,7 @@ pub enum IconName {
     Terminal,
     Trash,
     TrashAlt,
+    Triangle,
     TriangleRight,
     Undo,
     Unpin,
@@ -290,6 +291,7 @@ pub enum IconName {
     ZedAssistant,
     ZedAssistantFilled,
     ZedXCopilot,
+    X,
 }
 
 impl From<IconName> for Icon {