Re-implement fix in form #86

[jwallib]

I had to do a fresh install of the package and found the same bug I had previously so have re-implemented the fix that was dropped in commit f118011

[hanneoberman]

@all-contributors add @jwallib for bug

[hanneoberman]

Reproducing bug with current dev version of ggmice:

ggmice::plot_pattern(cbind(mice::nhanes, "empty var" = NA))
#> Error in `tidyselect::all_of()`:
#> ! Can't subset columns that don't exist.
#> ✖ Column `empty var` doesn't exist.
#> Backtrace:
#>      ▆
#>   1. ├─ggmice::plot_pattern(cbind(mice::nhanes, `empty var` = NA))
#>   2. │ └─... %>% ... at ggmice package/R/plot_pattern.R:109:4
#>   3. ├─dplyr::mutate(...)
#>   4. ├─tidyr::pivot_longer(...)
#>   5. ├─tidyr:::pivot_longer.data.frame(...)
#>   6. │ └─tidyr::build_longer_spec(...)
#>   7. │   └─tidyselect::eval_select(...)
#>   8. │     └─tidyselect:::eval_select_impl(...)
#>   9. │       ├─tidyselect:::with_subscript_errors(...)
#>  10. │       │ └─rlang::try_fetch(...)
#>  11. │       │   └─base::withCallingHandlers(...)
#>  12. │       └─tidyselect:::vars_select_eval(...)
#>  13. │         └─tidyselect:::walk_data_tree(expr, data_mask, context_mask)
#>  14. │           └─tidyselect:::eval_context(expr, context_mask, call = error_call)
#>  15. │             ├─tidyselect:::with_chained_errors(...)
#>  16. │             │ └─rlang::try_fetch(...)
#>  17. │             │   ├─base::tryCatch(...)
#>  18. │             │   │ └─base (local) tryCatchList(expr, classes, parentenv, handlers)
#>  19. │             │   │   └─base (local) tryCatchOne(expr, names, parentenv, handlers[[1L]])
#>  20. │             │   │     └─base (local) doTryCatch(return(expr), name, parentenv, handler)
#>  21. │             │   └─base::withCallingHandlers(...)
#>  22. │             └─rlang::eval_tidy(as_quosure(expr, env), context_mask)
#>  23. ├─tidyselect::all_of(vrb)
#>  24. │ └─tidyselect:::as_indices_impl(x, vars = vars, strict = TRUE)
#>  25. │   └─tidyselect:::chr_as_locations(x, vars, call = call, arg = arg)
#>  26. │     └─vctrs::vec_as_location(...)
#>  27. └─vctrs (local) `<fn>`()
#>  28.   └─vctrs:::stop_subscript_oob(...)
#>  29.     └─vctrs:::stop_subscript(...)
#>  30.       └─rlang::abort(...)

^{Created on 2023-07-17 with reprex v2.0.2}

Fixed after pull request:

ggmice::plot_pattern(cbind(mice::nhanes, "empty var" = NA))

^{Created on 2023-07-17 with reprex v2.0.2}