- Added an `Extension` field to `BlobMetadata` to store file extensions alongside existing metadata.
- Updated the `SaveBlob` method to handle file extensions, ensuring they are stored and retrieved correctly.
- Modified the `GetBlob` method to read blob data from the filesystem based on the stored extension.
- Enhanced the `Storage` struct to manage blob files in a specified directory, improving organization and access.
- Introduced utility functions for determining file extensions from MIME types, facilitating better file handling.
- Added comprehensive tests for new functionalities, ensuring robust behavior across blob operations.
