Reference Issues/PRs

This PR fixes #20266
A similar PR #20877 for this was opened long time back, but currently exists in stalled state.
Refering #21718 so this PR is also visible to people following that thread

What does this implement/fix? Explain your changes.

This PR adds two new metrics max_precision_at_recall_k & max_recall_at_precision_k.

Any other comments?

There were several comments under previous PR by @glemaitre . I've been able to resolve most of them, but I would like some clarifications about two points:-

• Implemented "precision at recall k" and "recall at precision k" #20877 (comment) -> There are two ways to approach this
  • Extend this page -> https://scikit-learn.org/stable/auto_examples/model_selection/plot_precision_recall.html?
  • Extend documentation of these newly introduced functions (Similar to how it is done for e.g. in here https://scikit-learn.org/dev/modules/generated/sklearn.metrics.class_likelihood_ratios.html#sklearn.metrics.class_likelihood_ratios)
• Implemented "precision at recall k" and "recall at precision k" #20877 (comment) -> Do you have anything in mind to avoid copying defination of precision and recall. We currently have the defination referenced at 4 different places
  • precision_recall_fscore_support
  • precision_score
  • recall_score
  • max_precision_at_recall_k
  • max_recall_at_precision_k
  • precision_recall_curve