patch 8.2.4193: cannot use an import in 'charconvert'

Problem:    Cannot use an import in 'charconvert'.
Solution:   Set the script context when evaluating 'charconvert'.  Also expand
            script-local functions in 'charconvert'.

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4193,
 /**/
     4192,
 /**/