debugger: Improve focus states (#29469)

Closes #ISSUE

Release Notes:

- N/A *or* Added/Fixed/Improved ...

crates/workspace/src/item.rs

@@ -214,12 +214,20 @@ pub struct TabContentParams {
     pub detail: Option<usize>,
     pub selected: bool,
     pub preview: bool,
+    /// Tab content should be deemphasized when active pane does not have focus.
+    pub deemphasized: bool,
 }
 
 impl TabContentParams {
     /// Returns the text color to be used for the tab content.
     pub fn text_color(&self) -> Color {
-        if self.selected {
+        if self.deemphasized {
+            if self.selected {
+                Color::Muted
+            } else {
+                Color::Hidden
+            }
+        } else if self.selected {
             Color::Default
         } else {
             Color::Muted

crates/workspace/src/pane.rs

@@ -2147,6 +2147,7 @@ impl Pane {
                 detail: Some(detail),
                 selected: is_active,
                 preview: is_preview,
+                deemphasized: !self.has_focus(window, cx),
             },
             window,
             cx,
@@ -3687,6 +3688,7 @@ impl Render for DraggedTab {
                 detail: Some(self.detail),
                 selected: false,
                 preview: false,
+                deemphasized: false,
             },
             window,
             cx,