Describe the workflow you want to enable

I would to make it easy to quickly introspect the default hyperparameter values of scikit-learn estimator in a jupyter notebook session.

Describe your proposed solution

The HTML widget returned by BaseEstimator._repr_mimebundle_ could display a tab with a tabular rendering of the content of the estimator.get_params() method.

In the case of meta-estimators with complex diagrams, we could optionally have an option to display this only for a subestimator of interest but I have no particular UI suggestion in mind.

Additional context

Loosely related to #21240 which is about another improvement, this time for the text rendering of complex estimators.