refactor(api): refactor all

- Replaced direct imports of `TriggerProviderID` and `ToolProviderID` from `core.plugin.entities.plugin` with imports from `models.provider_ids` for better organization.
- Refactored workflow node classes to inherit from a unified `Node` class, improving consistency and maintainability.
- Removed unused code and comments to clean up the implementation, particularly in the `workflow_trigger.py` and `builtin_tools_manage_service.py` files.

These changes enhance the clarity and structure of the codebase, facilitating easier future modifications.

api/core/entities/provider_entities.py

@@ -1,5 +1,5 @@
 from enum import StrEnum, auto
-from typing import Union
+from typing import Optional, Union
 
 from pydantic import BaseModel, ConfigDict, Field