range_to_quantile: Change Data from a Range Format to a Plain Quantile Format
Description
Transform data from a format that uses interval ranges to denote quantiles
to a format that uses quantiles only.
Given a data.frame that follows the structure shown in
quantile_example_data_long, the function outputs the same
data in a long format as (as shown in
quantile_example_data_long). This can be useful e.g. for
plotting. If you're data.frame is in a different format, consider running
quantile_to_wide first.