Data check

[AnFreTh]

This pull request includes several updates to the mambular package, focusing on version updates, enhancements to the classifier and regressor models, and improvements to input validation during preprocessing.

Version Update:

• Updated the version in mambular/__version__.py and pyproject.toml from 1.3.1 to 1.4.0. [1] [2]

Enhancements to Classifier and Regressor Models:

• Added num_classes parameter to build_model and fit methods in sklearn_base_classifier.py and sklearn_base_regressor.py, and updated the calls to the parent class methods accordingly. [1] [2] [3] [4] [5] [6]
• Updated sklearn_parent.py to include the num_classes parameter in the build_model and fit methods. [1] [2] [3] [4]

Preprocessing Improvements:

• Introduced a new utility function check_inputs in preprocessing/utils.py to validate input features and target values.
• Updated preprocessor.py to use the check_inputs function and added a new parameter min_unique_vals to the __init__ method. [1] [2] [3] [4]

Additional Imports:

• Added numpy import in sklearn_base_classifier.py to support the new functionality.