Using replace_with_na scoped variants

To reduce code repetition when replacing values with NA, use the "scoped variants" of replace_with_na():

The syntax of replacement looks like this:

~.x == "N/A"

This replaces all cases that are equal to "N/A".

~.x %in% c("N/A", "missing", "na", " ")

Replaces all cases that have "N/A", "missing", "na", or " ".

For the dataset pacman replace the same special missing values, "N/A", "missing", "na", and " ":