Phenonaut

Fixed
- bug in Phenonaut.merge_datasets
- bug in data.Datasets.groupby

Added
- merge_datasets method added to Phenonaut objects
- mp_value_score metric added to phenonaut.metrics.performance (doi:10.1177/1087057112469257)
- added __repr__ to Phenonaut objects

Changed
- Removed py3.10 style Unions, favouing the old style typing.Union

Fixed
- bug in the generation of Scree plots from fitted PCA transformers

Added
- groupby function to dataset, allowing splitting on one dataset into many

Added
- orient argument to write_boxplot_to_file allowing horizontal or vertical plotting.