collect_metrics: Compute and write all complexity metrics for a data set
In jorgenfrost/compost: Compute Complexity Metrics

Function that applies a number of intermediary functions (mostly varieties of wrap_long) to produces a series of data frames, that are written to file. The data frames that are written contains A) RCA values, B) similarity values, C) relatedness values (for all five metrics).

1 2	collect_metrics(df, country, output_dir, sim_method, t0_year, t1_year, t0_threshold, t1_threshold)

`df`	a data frame with four variables: time, region, unit, intensity
`country`	the country from where the data comes (fx "denmark")
`output_dir`	the directory the produced files should be written to (fx here("data/produced/country/"))
`sim_method`	the method used to compute similarities. Options are "proximity", "jaccard", "association"
`t0_year`	reference year (fx 2000)
`t1_year`	evaluation year (fx 2005)
`t0_threshold`	RCA value that units should be under in t0_year to be eligible for "new" in t1.
`t1_threshold`	RCA value that units should be equal to or over in t1_year to be eligible for "new" in t1.