Plot perf by sex

[sarakolding]

• [x] I have battle-tested on Overtaci (RMAPPS1279)
• [x] At least one of the commits is prefixed with either "fix:" or "feat:"

Fixes issue #393.

Notes for reviewers

We changed the name of the argument "prettify_bins" to "continuous_input_to_bins", since the functionality is whether is should be binned or not, rather than whether it should be pretty. Also, for both performance plots by age and sex, the metric is optional (default auc), though metric_fn_to_input can only handle roc_auc_score.

[MartinBernstorff]

Excellent! Can you please add a screenshot of the plot? :-)

[sarakolding]

Excellent! Can you please add a screenshot of the plot? :-)

[sarakolding]