Visualisation of in-fact routed params in metadata routing

[StefanieSenger]

Think about how to collect all the information to how sample_weight or groups had been routed (also for aliases) and the goal would be to make a dict that can be used for visualisation.

Return information as a dict on what got routed to which consumer (using validate_params) based on how the router is defined

• related to FEA SLEP006: debugging tool for sample props scikit-learn/scikit-learn#18936
• but different from ENH ascii visualisation for metadata routing scikit-learn/scikit-learn#31535, since #31535 is aimed to display all the possible routing, while the goal of this visualisation would be to display only the in-fact routed params