Set queue sizes by default on bulk/index thread pools
Now that we properly fixed the ability to set the queue size on the index / bulk thread pool, we should actually set them to a somehow reasonable value to protect from users potentially overflowing our system.

I suggest defaults to be 50 for bulk, and 200 for indexing.

Also, set the thread pool for get, which we should set (in a similar value to a "read" queue size we have today).
closes #3888