Remove base types where wrong
This merge request refactor the AssetModel.
All assets are now treated equally with that model.
The DataFormatModel was added to the particular case of DataFormat handling since not all data format shall be used everywhere. This models allows to either have only the standard created formats or also include the base types when appropriate.
Relevant issue(s) fixed
Fixes #260 (closed)
Fixes #246 (closed)