Test: Refactor test fixtures and add SDK session management tests (#8141)

### What problem does this PR solve?

- Consolidate HTTP API test fixtures using batch operations
(batch_add_chunks, batch_create_chat_assistants)
- Fix fixture initialization order in clear_session_with_chat_assistants
- Add new SDK API test suite for session management
(create/delete/list/update)

### Type of change

- [x] Add test cases
- [x] Refactoring

test/testcases/test_http_api/conftest.py

@@ -14,12 +14,14 @@
 #  limitations under the License.
 #
 
+from time import sleep
+
 import pytest
 from common import (
-    add_chunk,
+    batch_add_chunks,
+    batch_create_chat_assistants,
     batch_create_datasets,
     bulk_upload_documents,
-    create_chat_assistant,
     delete_chat_assistants,
     delete_datasets,
     delete_session_with_chat_assistants,
@@ -103,14 +105,14 @@ def clear_chat_assistants(request, api_key):
 
 @pytest.fixture(scope="function")
 def clear_session_with_chat_assistants(request, api_key, add_chat_assistants):
-    _, _, chat_assistant_ids = add_chat_assistants
-
     def cleanup():
         for chat_assistant_id in chat_assistant_ids:
             delete_session_with_chat_assistants(api_key, chat_assistant_id)
 
     request.addfinalizer(cleanup)
 
+    _, _, chat_assistant_ids = add_chat_assistants
+
 
 @pytest.fixture(scope="class")
 def add_dataset(request, api_key):
@@ -145,16 +147,8 @@ def add_chunks(api_key, add_document):
     dataset_id, document_id = add_document
     parse_documents(api_key, dataset_id, {"document_ids": [document_id]})
     condition(api_key, dataset_id)
-
-    chunk_ids = []
-    for i in range(4):
-        res = add_chunk(api_key, dataset_id, document_id, {"content": f"chunk test {i}"})
-        chunk_ids.append(res["data"]["chunk"]["id"])
-
-    # issues/6487
-    from time import sleep
-
-    sleep(1)
+    chunk_ids = batch_add_chunks(api_key, dataset_id, document_id, 4)
+    sleep(1)  # issues/6487
     return dataset_id, document_id, chunk_ids
 
 
@@ -168,10 +162,4 @@ def add_chat_assistants(request, api_key, add_document):
     dataset_id, document_id = add_document
     parse_documents(api_key, dataset_id, {"document_ids": [document_id]})
     condition(api_key, dataset_id)
-
-    chat_assistant_ids = []
-    for i in range(5):
-        res = create_chat_assistant(api_key, {"name": f"test_chat_assistant_{i}", "dataset_ids": [dataset_id]})
-        chat_assistant_ids.append(res["data"]["id"])
-
-    return dataset_id, document_id, chat_assistant_ids
+    return dataset_id, document_id, batch_create_chat_assistants(api_key, 5)