quickmt-uk-en, int8 CTranslate2

The quickmt/quickmt-uk-en translation model (CC BY 4.0, by quickmt) re-saved with int8 weights for CTranslate2, as used by the Yaku Translate app. Checked sentences give the same output as the float16 original.

The upstream weights were already int8; this copy is unchanged apart from the file layout.