Refactor system/version API to RESTful style (#13956)

### What problem does this PR solve?

Refactor version API to RESTful style. Python and go server API also
updated.
### Type of change

- [x] Refactoring



<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

## Release Notes

* **Refactor**
* Migrated core API endpoints to the `/api/v1/` namespace for improved
consistency and organization.
* Standardized system version, search, and chat list endpoints under the
new API versioning structure.

* **New Features**
* Added MinIO region configuration support, allowing specification of
storage engine regional settings via environment variables or
configuration files.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

test/testcases/test_web_api/common.py

@@ -35,6 +35,7 @@ MEMORY_API_URL = f"/api/{VERSION}/memories"
 MESSAGE_API_URL = f"/api/{VERSION}/messages"
 API_APP_URL = f"/{VERSION}/api"
 SYSTEM_APP_URL = f"/{VERSION}/system"
+SYSTEM_API_URL = f"/api/{VERSION}/system"
 LLM_APP_URL = f"/{VERSION}/llm"
 PLUGIN_APP_URL = f"/{VERSION}/plugin"
 SEARCHES_URL = f"/api/{VERSION}/searches"
@@ -113,7 +114,7 @@ def system_status(auth, params=None, *, headers=HEADERS):
 
 
 def system_version(auth, params=None, *, headers=HEADERS):
-    res = requests.get(url=f"{HOST_ADDRESS}{SYSTEM_APP_URL}/version", headers=headers, auth=auth, params=params)
+    res = requests.get(url=f"{HOST_ADDRESS}{SYSTEM_API_URL}/version", headers=headers, auth=auth, params=params)
     return res.json()