feat: add toc option in transformer node in ingestion pipeline (#11992)

### What problem does this PR solve?

Add TOC (Table of contents) option in Ingestion Pipeline canvas >
Transformer node

### Type of change

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

web/src/locales/en.ts

@@ -1925,6 +1925,7 @@ The Indexer will store the content in the corresponding data structures for the
       keywords: 'Keywords',
       questions: 'Questions',
       metadata: 'Metadata',
+      toc: 'Table of contents',
       fieldName: 'Result destination',
       prompts: {
         system: {

web/src/pages/agent/constant/pipeline.tsx

@@ -85,6 +85,7 @@ export enum ContextGeneratorFieldName {
   Keywords = 'keywords',
   Questions = 'questions',
   Metadata = 'metadata',
+  TableOfContents = 'toc',
 }
 
 export const FileId = 'File'; // BeginId

web/src/pages/agent/form/extractor-form/index.tsx

@@ -76,6 +76,8 @@ const ExtractorForm = ({ node }: INextOperatorForm) => {
             ></SelectWithSearch>
           )}
         </RAGFlowFormItem>
+        {form.getValues('field_name') !== 'toc' && (
+          <>
             <RAGFlowFormItem label={t('flow.systemPrompt')} name="sys_prompt">
               <PromptEditor
                 placeholder={t('flow.messagePlaceholder')}
@@ -89,6 +91,8 @@ const ExtractorForm = ({ node }: INextOperatorForm) => {
                 baseOptions={promptOptions}
               ></PromptEditor>
             </RAGFlowFormItem>
+          </>
+        )}
         <Output list={outputList}></Output>
       </FormWrapper>
       {visible && (