Robust Metrics Aggregation

[electronsandstuff]

This PR updates apply_feval_cutoff to be robust to badly indexed dataframes. Additional changes are as follows.

• New unit test for out of order and duplicate indices dataframes for apply_feval_cutoff
• Small cleanup to aggregate_metrics_feval_budget for readability. No change in functionality.
• comparison_table_to_latex is changed so that only equals signs after the first three lines are converted to \approx. This avoids issues when the experiment's name contains the equals sign.
• Fix another issue in comparison_table_to_latex where the summary line is not correctly printed unless the algorithm being compared with is in the last column.