feat(dynamic-sections): add custom css classes option (#4256)

packages/translation/src/lang/en.json

@@ -1163,6 +1163,9 @@
         "title": {
           "label": "Title"
         },
+        "customCssClasses": {
+          "label": "Custom css classes"
+        },
         "borderColor": {
           "label": "Border color"
         }

packages/validation/src/shared.ts

@@ -62,6 +62,7 @@ const emptySectionSchema = z.object({
 
 export const dynamicSectionOptionsSchema = z.object({
   title: z.string().max(20).default(""),
+  customCssClasses: z.array(z.string()).default([]),
   borderColor: z.string().default(""),
 });