Fix: Opensearch chunk management (#7802)

### What problem does this PR solve?

This PR solve the problems metioned in the
pr(https://github.com/infiniflow/ragflow/pull/7140) which is also
submitted by me

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [ ] New Feature (non-breaking change which adds functionality)
- [ ] Documentation Update
- [ ] Refactoring
- [ ] Performance Improvement
- [ ] Other (please describe):


### Introduction
I fixed the problems when using OpenSearch as the DOC_ENGINE, the
failures of pytest and the wrong API's return.
Mainly about delete chunk, list chunks, update chunk, retrieval chunk.
The pytest comand "cd sdk/python && uv sync --python 3.10 --group test
--frozen && source .venv/bin/activate && cd test/test_http_api &&
DOC_ENGINE=opensearch pytest test_chunk_management_within_dataset -s
--tb=short " is finally successful.

###Others
As some changes between Elasticsearch And Opensearch differ, some pytest
results about OpenSearch are correct and resonable. However, some pytest
params (skipif params) are incompatible. So I changed some pytest params
about skipif.

As a search engine programmer, I will still focus on the usage of vector
databases (especially OpenSearch) for the RAG stuff.
Thanks for your review

sdk/python/test/test_http_api/test_chunk_management_within_dataset/test_list_chunks.py

@@ -69,7 +69,7 @@ class TestChunksList:
         [
             ({"page_size": None}, 0, 5, ""),
             pytest.param({"page_size": 0}, 0, 5, "", marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") == "infinity", reason="Infinity does not support page_size=0")),
-            pytest.param({"page_size": 0}, 100, 0, "3013", marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") in [None, "elasticsearch"], reason="Infinity does not support page_size=0")),
+            pytest.param({"page_size": 0}, 100, 0, "3013", marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") in [None, "opensearch", "elasticsearch"], reason="Infinity does not support page_size=0")),
             ({"page_size": 1}, 0, 1, ""),
             ({"page_size": 6}, 0, 5, ""),
             ({"page_size": "1"}, 0, 1, ""),

sdk/python/test/test_http_api/test_chunk_management_within_dataset/test_retrieval_chunks.py

@@ -185,28 +185,28 @@ class TestChunksRetrieval:
                 0,
                 4,
                 "",
-                marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") == "infinity", reason="Infinity"),
+                marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") in ["infinity", "opensearch"], reason="Infinity"),
             ),
             pytest.param(
                 {"top_k": 1},
                 0,
                 1,
                 "",
-                marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") in [None, "elasticsearch"], reason="elasticsearch"),
+                marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") in [None, "opensearch", "elasticsearch"], reason="elasticsearch"),
             ),
             pytest.param(
                 {"top_k": -1},
                 100,
                 4,
                 "must be greater than 0",
-                marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") == "infinity", reason="Infinity"),
+                marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") in ["infinity", "opensearch"], reason="Infinity"),
             ),
             pytest.param(
                 {"top_k": -1},
                 100,
                 4,
                 "3014",
-                marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") in [None, "elasticsearch"], reason="elasticsearch"),
+                marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") in [None, "opensearch", "elasticsearch"], reason="elasticsearch"),
             ),
             pytest.param(
                 {"top_k": "a"},

sdk/python/test/test_http_api/test_chunk_management_within_dataset/test_update_chunk.py

@@ -146,7 +146,7 @@ class TestUpdatedChunk:
         [
             ("", 100, "<NotFound '404: Not Found'>"),
             pytest.param("invalid_dataset_id", 102, "You don't own the dataset invalid_dataset_id.", marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") == "infinity", reason="infinity")),
-            pytest.param("invalid_dataset_id", 102, "Can't find this chunk", marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") in [None, "elasticsearch"], reason="elasticsearch")),
+            pytest.param("invalid_dataset_id", 102, "Can't find this chunk", marks=pytest.mark.skipif(os.getenv("DOC_ENGINE") in [None, "opensearch","elasticsearch"], reason="elasticsearch")),
         ],
     )
     def test_invalid_dataset_id(self, get_http_api_auth, add_chunks, dataset_id, expected_code, expected_message):