`ard_stack(by)` argument not passed to `ard_missing()`

[ddsjoberg]

When we specify a by variable and .missing=TRUE, the missingness is not tabulated with the by arg specified.

TODO: If .overall=TRUE, .missing=TRUE, check that the overall missing are also included in results.

library(cards)
packageVersion("cards")
#> [1] '0.1.0.9023'

ard_stack(
  data = ADSL,
  by = ARM,
  ard_continuous(variables = "AGE", statistic = ~continuous_summary_fns("mean")),
  .missing = TRUE
)
#> {cards} data frame: 22 x 11
#>    group1 group1_level variable variable_level stat_name stat_label   stat
#> 1     ARM      Placebo      AGE                     mean       Mean 75.209
#> 2     ARM    Xanomeli…      AGE                     mean       Mean 74.381
#> 3     ARM    Xanomeli…      AGE                     mean       Mean 75.667
#> 4    <NA>                   AGE                    N_obs  Vector L…    254
#> 5    <NA>                   AGE                   N_miss  N Missing      0
#> 6    <NA>                   AGE                N_nonmiss  N Non-mi…    254
#> 7    <NA>                   AGE                   p_miss  % Missing      0
#> 8    <NA>                   AGE                p_nonmiss  % Non-mi…      1
#> 9    <NA>                   ARM        Placebo         n          n     86
#> 10   <NA>                   ARM        Placebo         N          N    254
#> ℹ 12 more rows
#> ℹ Use `print(n = ...)` to see more rows
#> ℹ 4 more variables: context, fmt_fn, warning, error

^{Created on 2024-05-09 with reprex v2.1.0}