Fix issue 87 parameter labels

[elong0527]

The issue #87 has been fixed.

Example:

devtools::load_all()

adsl <- forestly::forestly_adsl_3grp[1:100,]
adae <- forestly::forestly_adae_3grp[1:100,]
forestly::meta_forestly(
  dataset_adsl = adsl,
  dataset_adae = adae
) |>
  forestly::prepare_ae_forestly()|>
  forestly::format_ae_forestly(display = c("diff", "fig_diff")) |>
  forestly::ae_forestly()

adsl <- forestly::forestly_adsl_3grp[1:100,]
adae <- forestly::forestly_adae_3grp[1:100,]
forestly::meta_forestly(
  dataset_adsl = adsl,
  dataset_adae = adae
) |>
  forestly::prepare_ae_forestly()|>
  forestly::format_ae_forestly(display = c("n", "diff", "fig_diff")) |>
  forestly::ae_forestly()

adsl <- forestly::forestly_adsl_3grp[1:100,]
adae <- forestly::forestly_adae_3grp[1:100,]
forestly::meta_forestly(
  dataset_adsl = adsl,
  dataset_adae = adae
) |>
  forestly::prepare_ae_forestly()|>
  forestly::format_ae_forestly(display = c("prop", "diff", "fig_diff")) |>
  forestly::ae_forestly()