Fix issue 89 npop display

[elong0527]

The change should fix the order in plotly figure.

# Example demonstrating the fix for issue #89
# Consistent treatment group ordering between table and interactive plot

devtools::load_all()

# Create the interactive forest plot with 3 groups
library("forestly")

meta_forestly(
  dataset_adsl = forestly_adsl_3grp,
  dataset_adae = forestly_adae_3grp,
  parameter_term = "any;rel;ser",
  population_subset = SAFFL == "Y",
  observation_subset = SAFFL == "Y"
) |>
  prepare_ae_forestly(parameter = "any;rel;ser") |>
  format_ae_forestly() |>
  ae_forestly()