Feature: #84775 - Extend HMENU to support auto filling of special.value for special=language

See forge#84775

Description

This feature extends the HMENU content object to support the auto filling of special.value for language menus with the site languages available for the current site. Setting special.value to auto will include all available languages from the current site.

In case of special.value = auto the register languages_HMENU will be set with the determined IDs for the further usage in TypoScript.

Changed options

special.value

A list of comma separated language IDs (e.g. 0,1,2) or auto to load the list from site languages

Example TypoScript configuration

10 = HMENU
10 {
   special = language
   special.value = auto
}