Add fairness certificate link for fair models

[pplonski]

We will add links to Fairness Certificate for each model that pass fairness tests.

[pplonski]

When training AutoML with sensitive features we automatically apply bias check and mitigation. If your model satisfies fairness criterion we automatically generate the Fairness Compliance Certificate - you can download it and print.

Below are screenshots from AutoML training report and certificate. You can run example script to get familiar how fairness is working in MLJAR AutoML:

python examples/scripts/binary_classifier_adult_fairness.py