Add explicit character encoding specifications in 39 more RGL modules

To silence warnings and avoid potential problems after changing the default
encoding to UTF-8.

lib/src/finnish/QuestionFin.gf

@@ -1,3 +1,4 @@
+--# -coding=latin1
 concrete QuestionFin of Question = CatFin ** open ResFin, Prelude in {
 
   flags optimize=all_subs ;