I found the .dictionary files you were looking for here:
Download this app from Microsoft Store for Windows 10, Windows 10 Mobile. See screenshots, read the latest customer reviews, and compare ratings for Microsoft Bing Dictionary (Chinese-English). With the MDBG Chinese-English Dictionary for macOS you can quickly look up Chinese words using Chinese characters, Mandarin pinyin or the English definition. An internet connection is not required for using the dictionary, so you can use it anywhere, any time! Apple Mac OS X 10.11 El Capitan; Tips.
Chinese Dictionary For Mac
Chinese English Online Dictionary
/System/Library/Assets/com_apple_MobileAsset_DictionaryServices_dictionaryOSX/37 7ca105ade0203e0c89af6538f7b8ab0204dfba.asset/AssetData/Oxford Thesaurus of English.dictionary
/System/Library/Assets/com_apple_MobileAsset_DictionaryServices_dictionaryOSX/5a a689bfd471f943f70bd220ec2ed3849b7dbec3.asset/AssetData/Oxford Dictionary of English.dictionary
Free Chinese Dictionary
/System/Library/Assets/com_apple_MobileAsset_DictionaryServices_dictionaryOSX/f9 384c21fc7d64ad09992ad8bebbbfac16ad6a9d.asset/AssetData/Apple Dictionary.dictionary