Normalize URIs when uploading files

When submitting the file entity upload form, the "file destination" URI isn't passed through file_stream_wrapper_uri_normalize. In a basic case, it's possible for $file->uri to be needing relative paths to be resolved. However, for other stream wrappers, they may have special requirements in the structure of a URI. Combined with #2479523: Add a hook_file_stream_wrapper_uri_normalize_alter() hook this will let the media_internet module upload files to S3.