Feat: Add the option to use the knowledge graph to the retrieval form #3221 (#8968)

### What problem does this PR solve?

Feat: Add the option to use the knowledge graph to the retrieval form
#3221
### Type of change


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

web/src/pages/agent/constant.tsx

@@ -265,6 +265,8 @@ export const initialRetrievalValues = {
   empty_response: '',
   ...initialSimilarityThresholdValue,
   ...initialKeywordsSimilarityWeightValue,
+  use_kg: false,
+  cross_languages: [],
   outputs: {
     formalized_content: {
       type: 'string',