Allow batching multiple table alterations for the same config change

On startup recovery in MDB, there are times when we need to modify the table log settings. It's known that this is an expensive operation as WT will fsync after a WT_SESSION::alter() call on each table.

We've had complaints from users that have a large number of WT files about long startup times when the table log changes need to take place.

In hopes of improving this, I was wondering how feasible it would be to have WT allow batching multiple table alterations for the same config change. Right now we can only alter one table at a time in WT_SESSION::alter(). But I'm hoping that allowing batching of these changes will improve things and allow us to fsync less often.