If the best peptide in the aggregate report doesn't meet the aggregate inclusion threshold, still include its metadata in the metrics.json file

[susannasiebert]

Currently, if the best peptide in the aggregate report doesn't meet the aggregate inclusion threshold, no detailed data will be available for it. This behavior is confusing so the best peptide metadata should always be included in the metrics.json file so that we can display violin plots, anchor heatmaps, etc. for it.