feat: add optional datasetType to DatasetDTO and include in transform…

[jp-tosca]

This pull request introduces support for handling the datasetType property in the dataset DTO and ensures it is correctly included in payload transformations. The main changes are grouped by DTO updates and transformer logic enhancements.

DTO updates:

• Added an optional datasetType property to the DatasetDTO interface in src/datasets/domain/dtos/DatasetDTO.ts, allowing datasets to specify their type.

Transformer logic enhancements:

• Updated the transformDatasetModelToNewDatasetRequestPayload function in src/datasets/infra/repositories/transformers/datasetTransformers.ts to conditionally include datasetType in the payload if it is present in the dataset.