tm_outliers: Check validations

[mhallal1]

In tm_outliers, when are those validations below used and employed?
Please check and remove if unnecessary:

[donyunardi]

Acceptance Criteria

• Assess and remove unnecessary validation: line 322, 324, 330.
• Provide context on how the validations (the one that's being kept) are being used.

[chlebowa]

322 and 330 have been transferred to input validators.
324 remained and is used if the data provided warrants them. They don't kick in the example app because choices for categorical_var are specified like this:

ADSL <- synthetic_cdisc_data("latest")$adsl

fact_vars_adsl <- names(Filter(isTRUE, sapply(ADSL, is.factor)))
vars <- choices_selected(variable_choices(ADSL, fact_vars_adsl))

(...)

categorical_var = data_extract_spec(
  dataname = "ADSL",
  filter = filter_spec(
    vars = vars,
    choices = value_choices(ADSL, vars$selected),
    selected = value_choices(ADSL, vars$selected),
    multiple = TRUE
  )
),

but if the app developer has the power to pass invalid choices.

This is not a new issue.