Support languages="all" parameter in localize function

[gilsousampbx]

This PR handles languages=all param for localize function.

Summary of changes:

• Handle languages=all: returns original language name and all languages that:
  • are different than original language name
  • have hidden_prefix omitted from the property name
• Rename keep_every_language to keep_all_non_hidden_languages for clarity

Expected Result:

name -> raw.name
name_local -> raw.name
name_xx -> (raw.name_xx || raw.{hidden_prefix}_name_xx) && (name_xx != name)

Logic flow:

For each layer:
  For each feature:

    * For each property:
        If language property:
          If param languages=[all]:
            If property name = 'name':
              - Add {name} to {final_properties}  
            Else:
              - Remove hidden_prefix (if needed) from property name
              - Set value for {name_xx} key in {language_properties_to_be_added_to_final_properties}
          Else:
            Process with current logic - no change
    --- End of property loop ---
   
    Add {name_local} = {name} to {final_properties}
   
    * For each {name_xx} key in {language_properties_to_be_added_to_final_properties}:
        If {name_xx} value != {name} value:
          - Add {name_xx} to {final_properties}
    
  --- End of feature loop ---
--- End of layer loop ---
     

[kienbd]

✅ Unit tests

$ make test 

[kienbd]

Added PR description