Bug `create_var_from_codelist` when code is a negative number

[LiamHobby]

When the codelist contains a negative number and is used to generate a new column using create_var_from_codelist the resulting column is cast to a character variable rather than a numeric. See example below:

library(metacore)
library(tibble)
library(metatools)
library(dplyr)
data <- tribble(
  ~USUBJID, ~VAR1, ~VAR2,
  1, "M", "Male",
  2, "F", "Female",
  3, "F", "Female",
  4, "U", "Unknown",
  5, "M", "Male",
)
spec <- spec_to_metacore(metacore_example("p21_mock.xlsx"), quiet = TRUE) 

dm_spec <- metacore( 
  ds_spec = spec$ds_spec,
  ds_vars = spec$ds_vars,
  var_spec = spec$var_spec,
  value_spec = mutate(spec$value_spec, code_id = case_when(code_id != "SEX" ~ NA, TRUE ~ "SEX")),
  derivations = spec$derivations,
  supp = spec$supp, 
  codelist = structure(
    list(
      code_id = structure("SEX", label = "ID of the Code List"), 
                       name = "SEX", 
                       type = structure("code_decode", label = "Code List/Permitted Values/External Library"), 
                       codes = structure(list(structure(list(code = c(-999, 2, 3), decode = c("Female", "Male", "Unknown")),     row.names = c(NA, -3L), class = c("tbl_df", "tbl", "data.frame"))), label = "List of Codes")), row.names = c(NA, -1L),   class = c("tbl_df", "tbl", "data.frame"))) %>% 
select_dataset( "DM", quiet = TRUE)

create_var_from_codelist(data, dm_spec, VAR2, SEX)