* feat: integrate external model editor and handle message events for model updates
* feat: add CasbinEditor and IframeEditor components for model editing
* feat: add tabbed editor interface for CasbinEditor
* fix: Synchronize content between basic and advanced editors
* refactor: simplify CasbinEditor and ModelEditPage components
* refactor: Refactor CasbinEditor for improved iframe initialization and model synchronization
* refactor: update default state of CasbinEditor active tab to "advanced
* chore: add Apache License header to CasbinEditor.js and IframeEditor.js files
* refactor: update CasbinEditor class names for consistency
