Get vaccine coverage group for known serotype
Source:R/augment-pneumococcal.R
      derive_phe_pcv_group.RdFor the longitudinal oneumocococcal data, a range of useful serotype groups
is defined in the list avoncap::serotype_data. The avoncap::serotype_pcv_map gives a set of
mappings to (multiple) group headings that gives the overall serotype distribution by
vaccine.