add importFroms to each function

[KarinSchork]

for examples see Calibracurve Package

[KarinSchork]

#' @importFrom checkmate assertCharacter assertFlag
#' @importFrom magrittr %>%
#' @importFrom ggplot2 ggplot aes scale_x_continuous scale_y_continuous
#' geom_point scale_alpha_manual geom_line facet_wrap geom_rect geom_text
#' guides guide_legend theme theme_bw xlab ylab unit
#' @importFrom scales label_comma

[biwenzel]

need to recheck at the end, but most of these are covered with PR #62