[Low / Optional] Refactor storage-class-dropdown.tsx to Functional Architecture

AC:
Complexity: Medium | Impact: Low
Description: Perform a comprehensive refactor of the public/components/utils/storage-class-dropdown.tsx file.
Note: While the primary StorageClassDropdown component that uses Firehose has already been converted to a functional component, the file still contains legacy class-based logic or helper components that should be modernized to ensure architectural consistency across the utility directory.