Refactor sample pack handler to include creator information and enhance frontend components

Commit notes

- Updated the `GetSamplePacks` and `GetSamplePack` methods in the `SamplePackHandler` to preload user information for creator details, improving the response structure. - Enhanced the `SampleManagementProvider` to process and include additional metadata such as `creatorSlug` and `creatorName` for better sample management. - Refactored the `GainMeter` and `StoryPackPage` components to improve layout and maintainability, ensuring a consistent user experience across the application.