Prevent File Bulk Objects

There is an issue where bulk uploading a "file" object type causes details pages to error on a url lookup for a file md5 in the object_listing_row_widget.html template. This is because objects bulk upload only takes in a string for the "Value" while the normal object upload form takes in a local file path. Would need a click event for file browsing in handsontable, then ajax upload both json and file data which seems like a pain.

For now disable the "file" object uploads and add a note saying that object file uploads are not supported and that users can use the normal object upload form if they want to upload files.