fix(ui,types): Add Metadata form for collection (#11300)

**What**
- Adds missing Metadata form for collections
- Fixes type of metadata in update payload
- Fixes an issue where deleting the last row of a metadata form would prevent adding new ones.

Resolves SUP-784

packages/admin/dashboard/src/providers/router-provider/route-map.tsx

@@ -520,6 +520,11 @@ export const RouteMap: RouteObject[] = [
                         "../../routes/collections/collection-add-products"
                       ),
                   },
+                  {
+                    path: "metadata/edit",
+                    lazy: () =>
+                      import("../../routes/collections/collection-metadata"),
+                  },
                 ],
               },
             ],