Modify signature of Query/CacheQuery.getResultSize() and related offset/pagination methods to return long

The method exists in both new DSL and the classic query api.

It should be clarified whether this method and the related pagination methods should use int or long for specifying offsets within the data, also should decide if the total number of results / results per page is a long or an int - and update all involved method signatures to have a unitary treatment of this issue.

It appears that recent Lucene versions can offer the number of results as long, while older ones offer it as int (should be verified).

This issue was raised in a github conversation here: https://github.com/infinispan/infinispan/pull/2410