refactor(api/core/app/app_config/entities.py): Move Type to outside and add EXTERNAL_DATA_TOOL. (#7444)

api/core/workflow/nodes/start/entities.py

@@ -1,3 +1,7 @@
+from collections.abc import Sequence
+
+from pydantic import Field
+
 from core.app.app_config.entities import VariableEntity
 from core.workflow.entities.base_node_data_entities import BaseNodeData
 
@@ -6,4 +10,4 @@ class StartNodeData(BaseNodeData):
     """
     Start Node Data
     """
-    variables: list[VariableEntity] = []
+    variables: Sequence[VariableEntity] = Field(default_factory=list)