SSDM-13926: Working on the import/export API. Improving it.

.../sis/openbis/generic/asapi/v3/dto/exporter/AllFields.java

.../sis/openbis/generic/asapi/v3/dto/exporter/Attribute.java

...sis/openbis/generic/asapi/v3/dto/exporter/ExportData.java

...penbis/generic/asapi/v3/dto/exporter/ExportFieldType.java

...s/openbis/generic/asapi/v3/dto/exporter/ExportFormat.java

.../openbis/generic/asapi/v3/dto/exporter/ExportOptions.java

...s/openbis/generic/asapi/v3/dto/exporter/ExportResult.java

...enbis/generic/asapi/v3/dto/exporter/ExportableFields.java

...openbis/generic/asapi/v3/dto/exporter/ExportableKind.java

...enbis/generic/asapi/v3/dto/exporter/ExportablePermId.java

...openbis/generic/asapi/v3/dto/exporter/SelectedFields.java

.../openbis/generic/asapi/v3/dto/exporter/XLSTextFormat.java

...sis/openbis/generic/asapi/v3/dto/importer/ImportData.java

...s/openbis/generic/asapi/v3/dto/importer/ImportFormat.java

...sis/openbis/generic/asapi/v3/dto/importer/ImportMode.java

...penbis/generic/asapi/v3/dto/importer/ImportOperation.java

.../generic/asapi/v3/dto/importer/ImportOperationResult.java

.../openbis/generic/asapi/v3/dto/importer/ImportOptions.java

...s/openbis/generic/asapi/v3/dto/importer/ImportScript.java