Is there an easy way to connect a user's storefront session in a Theme Extension to the same user's checkout session in a Checkout Extension? There's a similar Community Post (https://community.shopify.com/c/shopify-apps/passing-data-from-theme-app-extension-to-checkout-ui-ex...) that mentions using the cart attribute field, but I need to find an alternative way due to some constraints. My current thoughts are to extract the Checkout Token (https://shopify.dev/docs/api/checkout-ui-extensions/2023-10/apis/checkout-token) in the Checkout Extension and subscribe our backend server to a Checkout Creation Webhook (https://shopify.dev/docs/api/admin-rest/2023-10/resources/webhook#event-topics) that can then use the Checkout Token to connect it to the Cart Token, which can then be traced back to the user's session. However, this seems overly complex. Are there any simpler solutions for this?