Add the capability to view the next available lease in TrackedLeaseCollection

[eemhu]

During rlo_06 development it was found out that the previous TrackedLeaseCollection only allowed to view if there was a next available lease without access to said lease without re-iterating through the collection.
Added the capability to next() where a stub will be provided if hasNext=false and index & lease will be provided if hasNext=true.

Description

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[kortemik]

Collection becomes a List if it has an order