Get label by language

[jairo-campos-JD]

Even if labels are defined for multiple languages, the Form Playground currently selects the first label in the list for display.

Could the Form Playground be updated to:

1. Allow the user to select/set a default language.
2. Select the label by the selected language.

[RubenVerborgh]

👍 Sounds like a good idea for LDflex as well.