refactor(messages): fold msg_attr into msg

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

src/nvim/buffer.c

@@ -3230,7 +3230,7 @@ void fileinfo(int fullname, int shorthelp, int dont_truncate)
     msg_start();
     n = msg_scroll;
     msg_scroll = true;
-    msg(buffer);
+    msg(buffer, 0);
     msg_scroll = n;
   } else {
     p = msg_trunc_attr(buffer, false, 0);