useUpload to support file metadata

[mazenkhalil]

We would like to request support for adding file metadata during file uploads, a feature currently offered by Supabase. Our use case involves using database triggers to automatically link uploaded attachments to another database table. This functionality relies on the ability to include metadata with file uploads, which is a powerful feature in Supabase. Implementing this capability would greatly enhance our workflow and enable seamless integration with our existing database triggers. Thank you for considering this addition.