show X on Tab when Cmd is pressed (#3241)

Task/Issue URL:
https://app.asana.com/0/1202406491309510/1206714287520246/f

**Description**:
- Display X button on Tab in compact mode when Cmd is pressed

**Steps to test this PR**:
1. Open many tabs to enter the overflown mode
2. Press Cmd, validate X button appears on a hovered tab when Cmd is
pressed

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**Definition of Done**:

* [ ] Does this PR satisfy our [Definition of
Done](https://app.asana.com/0/1202500774821704/1207634633537039/f)?

---
###### Internal references:
[Pull Request Review
Checklist](https://app.asana.com/0/1202500774821704/1203764234894239/f)
[Software Engineering
Expectations](https://app.asana.com/0/59792373528535/199064865822552)
[Technical Design
Template](https://app.asana.com/0/59792373528535/184709971311943)
[Pull Request
Documentation](https://app.asana.com/0/1202500774821704/1204012835277482/f)

DuckDuckGo/TabBar/View/TabBarViewItem.swift

@@ -333,6 +333,12 @@ final class TabBarItemCellView: NSView {
         if permissionButton.isShown {
             // make permission button from 16 to 24pt wide depending of available space
             permissionButton.frame = NSRect(x: x.rounded() - spacing.rounded(), y: bounds.midY - 12, width: 16 + spacing.rounded() * 2, height: 24)
+            x = permissionButton.frame.maxX
+        }
+        if closeButton.isShown {
+            // close button appears in place of favicon in compact mode
+            closeButton.frame = NSRect(x: x.rounded(), y: bounds.midY - 8, width: 16, height: 16)
+            x = closeButton.frame.maxX + spacing
         }
     }
 
@@ -609,7 +615,7 @@ final class TabBarViewItem: NSCollectionViewItem {
             cell.borderLayer.isHidden = !isSelected
         }
 
-        let showCloseButton = (isMouseOver && !widthStage.isCloseButtonHidden) || isSelected
+        let showCloseButton = (isMouseOver && (!widthStage.isCloseButtonHidden || NSApp.isCommandPressed)) || isSelected
         cell.closeButton.isShown = showCloseButton
         cell.faviconImageView.isShown = (cell.faviconImageView.image != nil) && (widthStage != .withoutTitle || !showCloseButton)
         updateSeparatorView()
@@ -837,6 +843,15 @@ extension TabBarViewItem: MouseClickViewDelegate {
         delegate?.tabBarViewItem(self, isMouseOver: isMouseOver)
         self.isMouseOver = isMouseOver
         view.needsLayout = true
+        eventMonitor = isMouseOver ? NSEvent.addLocalMonitorForEvents(matching: .flagsChanged) { [weak self] event in
+            if let self, widthStage.isCloseButtonHidden {
+                view.needsLayout = true
+            }
+            return event
+        } : nil
+
+        delegate?.tabBarViewItem(self, isMouseOver: isMouseOver)
+        self.isMouseOver = isMouseOver
     }
 
     func mouseClickView(_ mouseClickView: MouseClickView, otherMouseDownEvent: NSEvent) {