Import: some fixs and improvements. Add also new helper videos

src/Biopen/GeoDirectoryBundle/Admin/ImportAbstractAdmin.php

src/Biopen/GeoDirectoryBundle/Admin/ImportAdmin.php

...irectoryBundle/Controller/Admin/ImportAdminController.php

...irectoryBundle/EventListener/DatabaseIntegrityWatcher.php

...rces/views/admin/core_custom/custom-fields/file.html.twig

...dmin/core_custom/custom-fields/mapping-taxonomy.html.twig

...ryBundle/Resources/views/admin/list/list_import.html.twig

.../Resources/views/admin/list/list_import_dynamic.html.twig

...oDirectoryBundle/Services/ElementImportMappingService.php

web/test.json