Merge MultipleItemsBucketFactory
LPS-47465 Add factory to assist in the creation of the
ServiceTrackerMaps using common combinations
LPS-47465 Inner static classes to hold comparators and mappers used
frequently
LPS-47465 A comparator that compares ServiceReferences by a property in
inverse order.

We can use this comparator to prioritize services by "service.ranking"
property.
LPS-47465 Factory method to create a ServiceReferenceResolver that emits
the content of a property in a ServiceReference
LPS-47465 Added simple factory methods to create ServiceTrackerMaps,
single service or multiple services, using a property of the service
reference and prioritizing services references by "service.ranking"
property, if present.
LPS-47465 Add methods that allow a more refined configuration of the
map.

These parameter combinations allow to specify a custom
ServiceReferenceMapper or Comparator.