feat: add ingestion pipeline children delimiters configs (#11979)

### What problem does this PR solve?

Add children delimiters for Ingestion pipeline config

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

web/src/pages/agent/utils.ts

@@ -288,6 +288,11 @@ function transformSplitterParams(params: SplitterFormSchemaType) {
     ...params,
     overlapped_percent: Number(params.overlapped_percent) / 100,
     delimiters: transformObjectArrayToPureArray(params.delimiters, 'value'),
+
+    // Unset children delimiters if this option is not enabled
+    children_delimiters: params.enable_children
+      ? transformObjectArrayToPureArray(params.children_delimiters, 'value')
+      : [],
   };
 }
 
@@ -713,7 +718,7 @@ export function convertToObjectArray<T extends string | number | boolean>(
 
 /**
    * convert the following object into a list
-   * 
+   *
    * {
       "product_related": {
       "description": "The question is about product usage, appearance and how it works.",