Summarize absorb forms with atom-count-weighted scores
Source:R/nutrition.R
nutrition_summarize_absorb_global.RdPer metabolite, weighted contribution is `absorb_ratio * (c_absorb + n_absorb)`. For absorb form `C5N5` with ratio `0.2`, the weight is `10 * 0.2 = 2`. Values are summed across metabolites per group and absorb form.