* Update billing page data handling and version bump to 2.12.0
- Refactored billing page components to streamline data loading for subscriptions and orders.
- Introduced `getProductPlan` function to encapsulate product plan resolution logic.
- Updated `package.json` version from 2.11.0 to 2.12.0.
The commit refactors the previous implementation of using cache functions across several modules. They are now explicitly defined as loaders to improve readability and maintain a consistent style. This prevents the cache function calls from getting too nested and difficult to understand, especially in asynchronous cases. Additionally, the user session related hooks are deleted which were not used anymore.
