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
 
 ---

docs/references/python_api_reference.md

@@ -1460,21 +1460,13 @@ while True:
 ### Create session with agent
 
 ```python
-Agent.create_session(id,rag, **kwargs) -> Session
+Agent.create_session(**kwargs) -> Session
 ```
 
 Creates a session with the current agent.
 
 #### Parameters
 
-##### id: `str`, *Required*
-
-The id of agent
-
-##### rag:`RAGFlow object`
-
-The RAGFlow object
-
 ##### **kwargs
 
 The parameters in `begin` component.
@@ -1494,7 +1486,8 @@ from ragflow_sdk import RAGFlow, Agent
 
 rag_object = RAGFlow(api_key="<YOUR_API_KEY>", base_url="http://<YOUR_BASE_URL>:9380")
 AGENT_ID = "AGENT_ID"
-session = Agent.create_session(AGENT_ID, rag_object)
+agent = rag_object.list_agents(id = AGENT_id)[0]
+session = agent.create_session()
 ```
 
 ---
@@ -1571,7 +1564,8 @@ from ragflow_sdk import RAGFlow, Agent
 
 rag_object = RAGFlow(api_key="<YOUR_API_KEY>", base_url="http://<YOUR_BASE_URL>:9380")
 AGENT_id = "AGENT_ID"
-session = Agent.create_session(AGENT_id, rag_object)    
+agent = rag_object.list_agents(id = AGENT_id)[0]
+session = agent.create_session()    
 
 print("\n===== Miss R ====\n")
 print("Hello. What can I do for you?")
@@ -1592,8 +1586,6 @@ while True:
 
 ```python
 Agent.list_sessions(
-    agent_id,
-    rag
     page: int = 1, 
     page_size: int = 30, 
     orderby: str = "update_time", 
@@ -1640,11 +1632,42 @@ The ID of the agent session to retrieve. Defaults to `None`.
 from ragflow_sdk import RAGFlow
 
 rag_object = RAGFlow(api_key="<YOUR_API_KEY>", base_url="http://<YOUR_BASE_URL>:9380")
-agent_id = "2710f2269b4611ef8fdf0242ac120006"
-sessions=Agent.list_sessions(agent_id,rag_object)
+AGENT_id = "AGENT_ID"
+agent = rag_object.list_agents(id = AGENT_id)[0]
+sessons = agent.list_sessions()
 for session in sessions:
     print(session)
 ```
+---
+### Delete agent's sessions
+
+```python
+Agent.delete_sessions(ids: list[str] = None)
+```
+
+Deletes sessions of a agent by ID.
+
+#### Parameters
+
+##### ids: `list[str]`
+
+The IDs of the sessions to delete. Defaults to `None`. If it is not specified, all sessions associated with the agent will be deleted.
+
+#### Returns
+
+- Success: No value is returned.
+- Failure: `Exception`
+
+#### Examples
+
+```python
+from ragflow_sdk import RAGFlow
+
+rag_object = RAGFlow(api_key="<YOUR_API_KEY>", base_url="http://<YOUR_BASE_URL>:9380")
+AGENT_id = "AGENT_ID"
+agent = rag_object.list_agents(id = AGENT_id)[0]
+agent.delete_sessions(ids=["id_1","id_2"])
+```
 
 ---