select option group name ignores language strings

[dani-ooo]

when naming option groups with a language string, either as select or select_optgroup, it’s not displayed as it should.

form.field:
  label: THEME_X.LABEL
  type: select
  options:
    - THEME_X.SELECT_GROUP:
      - THEME_X.SELECT_OPTION1

in the example above, THEME_X.SELECT_OPTION1 uses the corresponding language string, as expected, but THEME_X.SELECT_GROUP appears exactly as “THEME_X.SELECT_GROUP”. needless to say i made sure the string was in the theme’s languages.yaml.

[w00fz]

Thanks