refactor(messages): fold msg_outtrans_attr into msg_outtrans

problem: there are too many different functions in message.c
solution: fold some of the functions into themselves

src/nvim/runtime.c

@@ -2329,7 +2329,7 @@ void ex_scriptnames(exarg_T *eap)
       vim_snprintf(IObuff, IOSIZE, "%3d: %s", i, NameBuff);
       if (!message_filtered(IObuff)) {
         msg_putchar('\n');
-        msg_outtrans(IObuff);
+        msg_outtrans(IObuff, 0);
         line_breakcheck();
       }
     }