Show fold indicators (#3334)

Release Notes:

- N/A

crates/gpui2/src/window.rs

@@ -216,7 +216,7 @@ pub struct Window {
 
 // #[derive(Default)]
 pub(crate) struct Frame {
-    element_states: HashMap<GlobalElementId, AnyBox>,
+    pub(crate) element_states: HashMap<GlobalElementId, AnyBox>,
     mouse_listeners: HashMap<TypeId, Vec<(StackingOrder, AnyMouseListener)>>,
     pub(crate) dispatch_tree: DispatchTree,
     pub(crate) focus_listeners: Vec<AnyFocusListener>,
@@ -2471,7 +2471,7 @@ impl From<SmallVec<[u32; 16]>> for StackingOrder {
 #[derive(Clone, Debug, Eq, PartialEq, Hash)]
 pub enum ElementId {
     View(EntityId),
-    Number(usize),
+    Integer(usize),
     Name(SharedString),
     FocusHandle(FocusId),
 }
@@ -2484,13 +2484,13 @@ impl From<EntityId> for ElementId {
 
 impl From<usize> for ElementId {
     fn from(id: usize) -> Self {
-        ElementId::Number(id)
+        ElementId::Integer(id)
     }
 }
 
 impl From<i32> for ElementId {
     fn from(id: i32) -> Self {
-        Self::Number(id as usize)
+        Self::Integer(id as usize)
     }
 }