Add a plot for number_of_repetitions when type is all and level is resource

[richierocks]

This is currently not supported. It returns a function, which is confusing.

library(edeaR)
data(sepsis, package = "eventdataR")
n_reps <- number_of_repetitions(sepsis, level = "resource")
## Using default type: all
plot(n_reps)
## function (...) 
##   tags$p(...)
## <bytecode: 0x1022c4c50>
##   <environment: namespace:htmltools>

This ought to show a bar plot of the absolute number of repetitions by resource (to match the behavior when level = "activity").