Make defaultModels use ascii_name over utf8_name
Make defaultModels use ascii_name over utf8_name

- The ascii_name is envisioned for URLs while the utf8_name is for displaying.

- Also add {get,set}DefaultSourceLanguage functions.

- Relates to #356

lingdb/CoBL-public,lingdb/CoBL-public,lingdb/CoBL-public,lingdb/CoBL-public