### What problem does this PR solve?
- rename rmSpace to remove_redundant_spaces
- move clean_markdown_block to common module
- add unit tests for remove_redundant_spaces and clean_markdown_block
### Type of change
- [x] Refactoring
---------
Signed-off-by: Jin Hai <haijin.chn@gmail.com>
### What problem does this PR solve?
Fix a small non-blocking main workflow bug about chunk update When
OpenSearch is the doc engine.
When you wanna enable/disable a chunk in the web-page “Knowledge Base /
Dataset / Chunk”, the bug ocurred.
<img width="2388" height="662" alt="image"
src="https://github.com/user-attachments/assets/575987a0-c929-4589-bfa0-ba54e137cfd9"
/>
The reaseon why it ocurred is that some api params between OpenSearch
and ES differs. It functioned well no matter enable/disable/rewrite the
chunk after I fixed. I also checked the result when using the chat
web-page.
<img width="2394" height="660" alt="image"
src="https://github.com/user-attachments/assets/8b899dc6-d769-4e80-8dd8-ad0fbbca5f78"
/>
I will still focus on vector-database espeically OpenSearch.
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)
Co-authored-by: 张雨豪 <zhangyh80@chinatelecom.cn>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>
