LPS-47465 Add MultipleItemsBucketFactory.

This factory returns CollectionBuckets. These buckets hold and return a
collection of the services.

In this case the comparator is used to sort the services in the
collection, so they are going to be returned in this order to the
consumer of the API.
LPS-47465 Keep a sorted set with the references using the comparator.

Then we keep a collection (list) that is the one that we are going to
return to the consumers without contention. The class synchronizes the
rest of the operations.
LPS-47465 Convenience method to rebuild the collection of services from
the ordered set.
LPS-47465 Implement methods of the interface
LPS-47465 Add missing author tag
LPS-47465 SF
LPS-47465 SF
LPS-47465 SF