incorrect encoding for east asia characters

[testercwt]

The constants.jl contains incorrect information for east asia character

here is the correct (east asia character) encodings as below

118 => "CP950",
119 => "EUC-TW",
123 => "BIG5-HKSCS",
125 => "GB18030",
126 => "CP936",
134 => "EUC-JP",
136 => "CP932",
138 => "CP932",
140 => "EUC-KR",
141 => "CP949"

---

ref
https://support.sas.com/documentation/onlinedoc/dfdmstudio/2.6/dmpdmsug/Content/dfU_Encodings_SAS.html

[tk3369]

Thanks. Do you mind submitting a PR? Do you have any test files with these encodings?

[testercwt]

fixed