feat: add background fill functionality for layers

- Implemented FillLayerBackgroundCommand to fill the background of layers with a specified color.
- Introduced BackgroundFillManager to manage background fill operations.
- Updated LayerManager to include fillLayerBackground method.
- Enhanced LayersPanel with a color picker for filling layer backgrounds.
- Modified RasterizeLayerCommand to reflect changes in terminology and functionality.
- Adjusted LayerSort to ensure filled layers are rendered at the correct z-index.
- Updated relevant utility functions and components to support new fill feature.

src/component/Canvas/CanvasEditor/managers/brushes/fabric.brushes.js

@@ -12,6 +12,7 @@
  * - https://mrdoob.com/projects/harmony/
  * - http://perfectionkills.com/exploring-canvas-drawing-techniques/
  */
+import { fabric } from "fabric-with-all";
 import { sprayBrushDataUrl } from "./data/sprayBrushData.js";
 
 (function (fabric) {