GPv3: Delete operator

Adds the delete operator to edit mode grease pencil, and also adds it to the delete menu.

Pull Request: https://projects.blender.org/blender/blender/pulls/111571

scripts/startup/bl_ui/space_view3d.py

@@ -5007,6 +5007,10 @@ class VIEW3D_MT_edit_greasepencil_delete(Menu):
     def draw(self, _context):
         layout = self.layout
 
+        layout.operator("grease_pencil.delete")
+        
+        layout.separator()
+
         layout.operator_enum("grease_pencil.dissolve", "type")
 
         layout.separator()