Feat: add 'delete' for agent's sessions api and unify apis of agent sdk (#5525)

### What problem does this PR solve?

Add sessions deletion support for agent in http and python api

### Type of change

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

---------

Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

docs/references/http_api_reference.md

@@ -2914,6 +2914,62 @@ Failure:
 
 ---
 
+### Delete agent's sessions
+
+**DELETE** `/api/v1/agents/{agent_id}/sessions`
+
+Deletes sessions of a agent by ID.
+
+#### Request
+
+- Method: DELETE
+- URL: `/api/v1/agents/{agent_id}/sessions`
+- Headers:
+  - `'content-Type: application/json'`
+  - `'Authorization: Bearer <YOUR_API_KEY>'`
+- Body:
+  - `"ids"`: `list[string]`
+
+##### Request example
+
+```bash
+curl --request DELETE \
+     --url http://{address}/api/v1/agents/{agent_id}/sessions \
+     --header 'Content-Type: application/json' \
+     --header 'Authorization: Bearer <YOUR_API_KEY>' \
+     --data '
+     {
+          "ids": ["test_1", "test_2"]
+     }'
+```
+
+##### Request Parameters
+
+- `agent_id`: (*Path parameter*)  
+  The ID of the associated agent.
+- `"ids"`: (*Body Parameter*), `list[string]`  
+  The IDs of the sessions to delete. If it is not specified, all sessions associated with the specified agent will be deleted.
+
+#### Response
+
+Success:
+
+```json
+{
+    "code": 0
+}
+```
+
+Failure:
+
+```json
+{
+    "code": 102,
+    "message": "The agent doesn't own the session cbd31e52f73911ef93b232903b842af6"
+}
+```
+---
+
 ## AGENT MANAGEMENT
 
 ---