Upload file using MultipartFile

[YevhenKlymenko]

Hi,
Is it possible to upload files using MultipartFile?
Using a file path isn’t very suitable, since it requires saving temporary files on the server and then manually deleting them. With MultipartFile, you can work directly with the byte stream without saving the file, which is much more convenient.
Or it can be array of bytes, or InputStream

[sashirestela]

@YevhenKlymenko Thanks for using simple-openai. Please, feel free to create a PR with your approach.