Support adding Graphic and Topstitches

Purpose：

Support users with more customization options for zippers, including adding topstitch instances and Graphic instances.

Operation Path:

Adding Topstitch：Assets▶ Segment Topstitch/Free Topstitch

Edit Topstitch：Assets ▶ Edit Topstitch

Adding Graphic：Assets ▶ Graphic

Edit Graphic：Assets ▶ Transform Graphic

Operation Instructions:

The operations for adding and editing Graphic and Topstitches on zippers are the same as those for regular pattern pieces.