Error when uploading notebook file type #35
Description
When using the Upload Files functionality inside the DrivesFileBrowser, the operation fails for certain file types (e.g. notebooks).
This issue is caused by the specific file formatting - JupyterLab needs a different body formatting when viewing files, compared to some other drives' providers (e.g. in S3 buckets). The backend contents manager already formats the body of files according to this, but the logic needs to be updated.
When uploading a notebook, the save functionality in the frontend contents manager receives in the options parameters the type file and format base64, opposed to type notebook and format json it receives when saving an already existing notebook. This is probably the cause of the wrong body formatting.