[dictionary] Description override should be per-language, not global

[driusan]

The parameter_type_override from the dictionary and datadict module allows a field description to be overridden. However, there is one override per language. This does not make sense in a multi-lingual context, as the user expects the override to only override their current interface language.

We should add a language dimension to the parameter_type_override functionality where either it only overrides the current language, or explicitly asks the user which language they want to override.