Implement creator application functionality in backend and frontend

Commit notes

- Added a new `CreatorHandler` to manage creator application routes, including methods for getting application status and submitting applications. - Introduced `CreatorApplication` model to handle creator application data in the database. - Updated the main API routing to include protected routes for creator applications. - Enhanced frontend with a new `CreatorApply` component for users to apply to become creators, including application status handling and submission logic. - Updated routing and layout to accommodate the new creator application flow, ensuring a seamless user experience for potential creators.