Export to file library behaviour does not match 'download file' behaviour

Describe the Bug Scenario: Tables with many columns are used in Directus that are managed externally and haven't been fully configured in Directus (by adding them to directus_collections, directus_relations, directus_fields etc). Users need the ability to export and re-import exported data. If you are developing an application where admin configuration is not a high priority, the above scenario is a likely one. Point Directus at a database and it should just work for simple columns (at least those without relations) without needing to add tedious config for each table and field. Ideally it would work with relations without any additional config, with config added simply to tweak things rather than be necessary to make Directus work. Like how [Hasura ]( scans your database schema and doesn't need you to add config (or create the tables and fields inside Hasura itself) to make it work properly. It detects column types and relations and just works. To Reproduce Expor…