Use filtered output in ordinary commands

Many otherwise ordinary commands choose to use unfiltered output
rather than filtered.  I don't think there's any reason for this, so
this changes many such commands to use filtered output instead.

Note that complete_command is not touched due to a comment there
explaining why unfiltered output is believed to be used.

gdb/cp-support.c

@@ -2185,7 +2185,7 @@ first_component_command (const char *arg, int from_tty)
   memcpy (prefix, arg, len);
   prefix[len] = '\0';
 
-  printf_unfiltered ("%s\n", prefix);
+  printf_filtered ("%s\n", prefix);
 }
 
 /* Implement "info vtbl".  */