Refa: HTTP API update dataset / test cases / docs (#7564)

### What problem does this PR solve?

This PR introduces Pydantic-based validation for the update dataset HTTP
API, improving code clarity and robustness. Key changes include:
1. Pydantic Validation
2. ​​Error Handling
3. Test Updates
4. Documentation Updates
5. fix bug: #5915

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [x] Documentation Update
- [x] Refactoring

sdk/python/test/libs/utils/hypothesis_utils.py

@@ -0,0 +1,28 @@
+#
+#  Copyright 2025 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 hypothesis.strategies as st
+
+
+@st.composite
+def valid_names(draw):
+    base_chars = "abcdefghijklmnopqrstuvwxyz_"
+    first_char = draw(st.sampled_from([c for c in base_chars if c.isalpha() or c == "_"]))
+    remaining = draw(st.text(alphabet=st.sampled_from(base_chars), min_size=0, max_size=128 - 2))
+
+    name = (first_char + remaining)[:128]
+    return name.encode("utf-8").decode("utf-8")