Moved convertToImage, createMaskFromImageSrc, and canvasToMaskImage from MaskProcessingUtils and mask_utils to ImageUtils for better modularity and reuse. Updated imports in dependent modules to use the new locations. Removed duplicate implementations from mask_utils and MaskProcessingUtils.
Replaces direct usage of document.createElement('canvas') and manual context setup with the createCanvas utility across multiple utility modules. This change improves code consistency, reduces duplication, and centralizes canvas/context creation logic. Also updates notification usage in ClipboardManager to use showNotification and showInfoNotification utilities.
