Refactor: enhance graphrag - part 2 (#14972)

### What problem does this PR solve?
1. expose batch_chunk_token_size for configuration
2. retrieve chunks when build subgraph for the doc, not retreive all
docs chunks at the begining
3. get all chunks for a document, used to be hard coded 10000
4. delete not used method run_graphrag

### Type of change

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

Follow on: #14617

web/src/pages/dataset/dataset-setting/form-schema.ts

@@ -70,6 +70,12 @@ export const formSchema = z
             method: z.string().optional(),
             resolution: z.boolean().optional(),
             community: z.boolean().optional(),
+            batch_chunk_token_size: z
+              .number()
+              .int()
+              .min(512)
+              .max(8196)
+              .optional(),
           })
           .refine(
             (data) => {

web/src/pages/dataset/dataset-setting/index.tsx

@@ -103,6 +103,7 @@ export default function DatasetSettings() {
           use_graphrag: true,
           entity_types: initialEntityTypes,
           method: MethodValue.Light,
+          batch_chunk_token_size: 4096,
         },
         metadata: {
           type: 'object',