feat(graph_engine): Support pausing workflow graph executions (#26585)

Signed-off-by: -LAN- <laipz8200@outlook.com>

api/tests/integration_tests/workflow/nodes/test_http.py

@@ -5,10 +5,11 @@ from urllib.parse import urlencode
 import pytest
 
 from core.app.entities.app_invoke_entities import InvokeFrom
-from core.workflow.entities import GraphInitParams, GraphRuntimeState, VariablePool
+from core.workflow.entities import GraphInitParams
 from core.workflow.graph import Graph
 from core.workflow.nodes.http_request.node import HttpRequestNode
 from core.workflow.nodes.node_factory import DifyNodeFactory
+from core.workflow.runtime import GraphRuntimeState, VariablePool
 from core.workflow.system_variable import SystemVariable
 from models.enums import UserFrom
 from tests.integration_tests.workflow.nodes.__mock.http import setup_http_mock
@@ -174,13 +175,13 @@ def test_custom_authorization_header(setup_http_mock):
 @pytest.mark.parametrize("setup_http_mock", [["none"]], indirect=True)
 def test_custom_auth_with_empty_api_key_does_not_set_header(setup_http_mock):
     """Test: In custom authentication mode, when the api_key is empty, no header should be set."""
-    from core.workflow.entities.variable_pool import VariablePool
     from core.workflow.nodes.http_request.entities import (
         HttpRequestNodeAuthorization,
         HttpRequestNodeData,
         HttpRequestNodeTimeout,
     )
     from core.workflow.nodes.http_request.executor import Executor
+    from core.workflow.runtime import VariablePool
     from core.workflow.system_variable import SystemVariable
 
     # Create variable pool