Console core package: Convert SecretFormWrapper component in create-secret.tsx from class component to functional component

One of the steps of the migration strategy is start using the v6 API for components that are passed to the `CompatRoute` component, based on the [migration strategy guide|https://github.com/remix-run/react-router/discussions/8753.]. This route now has both v5 and v6 routing contexts, so we can start migrating component code to v6.

If the component is a class component, you'll need to convert it to a function component first so that you can use hooks.

The SecretFormWrapper component in /frontend/public/components/secrets/create-secret.tsx needs to use the v6 useNavigate hook, which requires it to be converted from a class component to a functional component. 

AC: ScretFormWrapper component in create-secret.tsx is rewritten from class component to functional component.