perf(cdk-experimental/column-resize): add debounce to column header hover to prevent excessive handler rendering

Add a debounceTime(300) to the headerCellHoveredDistinct observable to delay the rendering of handlers until the user hovers over the header for at least 300ms. This prevents unnecessary rendering of handlers during quick cursor movements.

Author: danielolaru91

src/cdk-experimental/column-resize/resizable.ts

@@ -284,7 +284,9 @@ export abstract class Resizable<HandleComponent extends ResizeOverlayHandle>
   }
 
   private _updateOverlayHandleHeight() {
-    this.overlayRef!.updateSize({height: this.elementRef.nativeElement!.offsetHeight});
+    requestAnimationFrame(() => {
+      this.overlayRef!.updateSize({height: this.elementRef.nativeElement!.offsetHeight});
+    })
   }
 
   private _applySize(sizeInPixels: number, previousSize?: number): void {