Add dataset navigation search for agentic RAG (#18218)

### Summary

Add dataset navigation search for agentic RAG.

dataset_navigation_search() calls
dataset_api_service.search_dataset_layers with mode as "nav_doc"

test/unit_test/api/apps/services/test_dataset_api_service_list_datasets.py

@@ -32,7 +32,6 @@ from unittest.mock import MagicMock
 
 import pytest
 
-
 pytestmark = pytest.mark.p2
 
 
@@ -97,6 +96,7 @@ def _load_list_datasets_module(monkeypatch, *, kbs, parsing_status_by_kb):
         FileSource=SimpleNamespace(KNOWLEDGEBASE="knowledgebase"),
         PipelineTaskType=SimpleNamespace(),
         StatusEnum=SimpleNamespace(),
+        RetCode=SimpleNamespace(),
         ModelTypeBinary=_StubModelTypeBinary,
     )
     _stub(
@@ -175,6 +175,8 @@ def _load_list_datasets_module(monkeypatch, *, kbs, parsing_status_by_kb):
         thread_pool_exec=MagicMock(),
         thread_pool_exec_long_time=MagicMock(),
     )
+    _stub(monkeypatch, "rag.advanced_rag", __path__=[])
+    _stub(monkeypatch, "rag.advanced_rag.knowlege_compile", __path__=[])
     _stub(
         monkeypatch,
         "rag.advanced_rag.knowlege_compile.wiki",

test/unit_test/api/apps/services/test_delete_datasets.py

@@ -17,8 +17,8 @@
 
 import importlib.util
 import sys
-from pathlib import Path
 from enum import IntEnum
+from pathlib import Path
 from types import ModuleType, SimpleNamespace
 from unittest.mock import MagicMock
 
@@ -155,8 +155,16 @@ def _load_delete_datasets_module(monkeypatch, *, f2d_rows, file_filter_delete):
         ),
         StatusEnum=SimpleNamespace(),
         LLMType=SimpleNamespace(),
+        RetCode=SimpleNamespace(),
         ModelTypeBinary=_StubModelTypeBinary,
     )
+    _stub(monkeypatch, "rag.advanced_rag", __path__=[])
+    _stub(monkeypatch, "rag.advanced_rag.knowlege_compile", __path__=[])
+    _stub(
+        monkeypatch,
+        "rag.advanced_rag.knowlege_compile.wiki",
+        WIKI_PAGE_COMPILE_KWD="wiki",
+    )
     _stub(
         monkeypatch,
         "rag.nlp.search",