Plot H12 and G123 in cohort pages with Hampel filter applied

[alimanfoo]

We are using the Hampel filter to clear up noise in the H12 scans before we fit signals. But in the cohort pages we show the unfiltered H12 and G123 data. It might be a good idea to show the filtered data, as it will have less isolated outliers and help to focus attention on the stronger signals.

Would probably require some work upstream in malariagen_data -- malariagen/malariagen-data-python#351