Set content type for uploaded files in minio

On integrating the file upload in the frontend, I realized that all the files are returned from minio as octed streams. While this makes it easy to download them, some of them could be rendered in the browser when a more specific content type can be set.

Technically it should be easy to do so with the put_object method in the minio client https://docs.min.io/docs/python-client-api-reference.html (and maybe a lookup table for the supported file formats).