Add DALY components

Weights from Gunda et al, 2016

daly_components(
  x,
  lifespan = 63,
  episode_length = 0.01375,
  severe_episode_length = 0.04795,
  weight1 = 0.211,
  weight2 = 0.195,
  weight3 = 0.172,
  severe_weight = 0.6
)

Arguments

x	Model output
lifespan	Average life expectancy
episode_length	Average length of clinical episode
severe_episode_length	Average length of severe episode
weight1	Disability weight age group 1
weight2	Disability weight age group 2
weight3	Disability weight age group 3
severe_weight	Disability weight severe malaria