create the python sdk to return version (#1039)

### What problem does this PR solve?

Create python SDK to return the version of RAGFlow.

### Type of change

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

---------

Co-authored-by: cecilia-uu <konghui1996@163.com>

SDK/python/ragflow/__init__.py

@@ -0,0 +1,3 @@
+import importlib.metadata
+
+__version__ = importlib.metadata.version("ragflow")

SDK/python/ragflow/ragflow.py

@@ -0,0 +1,28 @@
+#
+#  Copyright 2024 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+import os
+import dotenv
+import typing
+from api.utils.file_utils import get_project_base_directory
+
+
+def get_versions() -> typing.Mapping[str, typing.Any]:
+    dotenv.load_dotenv(dotenv.find_dotenv())
+    return dotenv.dotenv_values()
+
+
+def get_rag_version() -> typing.Optional[str]:
+    return get_versions().get("RAGFLOW_VERSION", "dev")