Improve messaging for print_ard_conditions()

[ddsjoberg]

ard <- cards::ADSL |> 
  cards::ard_continuous(
    variable = AGEGR1,
    statistic = ~list(kurtosis = \(x) e1071::kurtosis(x))
  )

# do we really need to print 'returned during `print_ard_conditions()`'? Seems unnecessary because that is not where the error originated.
library(cards)
print_ard_conditions(ard)
#> The following errors were returned during `print_ard_conditions()`:
#> ✖ For variable `AGEGR1` and "kurtosis" statistic: non-numeric argument to
#>   binary operator
#> The following warnings were returned during `print_ard_conditions()`:
#> ! For variable `AGEGR1` and "kurtosis" statistic: argument is not numeric or
#>   logical: returning NA

# when the function is namespaced, we get extra prints of `::` `cards`
cards::print_ard_conditions(ard)
#> The following errors were returned during `::()`, `cards()`, and
#> `print_ard_conditions()`:
#> ✖ For variable `AGEGR1` and "kurtosis" statistic: non-numeric argument to
#>   binary operator
#> The following warnings were returned during `::()`, `cards()`, and
#> `print_ard_conditions()`:
#> ! For variable `AGEGR1` and "kurtosis" statistic: argument is not numeric or
#>   logical: returning NA

^{Created on 2024-10-16 with reprex v2.1.1}