* Add a Begin of the deletion third mode for `projects_storages.project_folder_mode`. The value is `managed`.
* Add aEnd of the deletion table `last_managed_project_folder`(project\_id, origin\_folder\_id). Have a dedicated description for this table (why do we need it?). Begin of the insertion
* Columns: project\_storages\_id `int`, origin\_folder\_id `int`, mode `enum project_folders_modes`
* PK: all columsEnd of the insertion