Support CP238

[qimuxi1990]

It seems iconv-lite does not support CP238 now. I do neither see it from either their documentation nor passed it through this parser.
I noticed CP238 is commented as 'eastern European' but I do not know what is the alternative of it in iconv-lite.
I have replaced it with \fcharset0 in my work case, but wondering about the correct code page.
Thank you.

Example input:

{\rtf1\ansi\ansicpg1252\deff0\nouicompat\deflang1033{\fonttbl{\f0\fnil\fcharset238 Microsoft Sans Serif;}{\f1\fnil Microsoft Sans Serif;}{\f2\fnil\fcharset2 Symbol;}}
{\colortbl ;\red0\green0\blue0;}
{\*\generator Riched20 10.0.19041}\viewkind4\uc1 
\pard{\pntext\f2\'B7\tab}{\*\pn\pnlvlblt\pnf2\pnindent0{\pntxtb\'B7}}\cf1\f0\fs16\lang1038 Megan would be only after 9:30\cf0\f1\fs17\lang1033\par
{\pntext\f2\'B7\tab}\cf1\f0\fs16\lang1038 Nancy helped with the chemistry instrument\cf0\f1\fs17\lang1033\par
{\pntext\f2\'B7\tab}\cf1\f0\fs16\lang1038 They do urine and blood gas but she wasn't aloud to give out any further information, i have to talk with Megan about this later on today\cf0\f1\fs17\lang1033\par
}

{\rtf1\ansi\ansicpg1252\deff0\nouicompat\deflang1033{\fonttbl{\f0\fnil\fcharset238 Tahoma;}{\f1\fnil Tahoma;}{\f2\fnil\fcharset2 Symbol;}}
{\*\generator Riched20 10.0.19041}\viewkind4\uc1 
\pard{\pntext\f2\'B7\tab}{\*\pn\pnlvlblt\pnf2\pnindent0{\pntxtb\'B7}}\f0\fs16\lang1038 no answer\f1\fs17\lang1033\par
}