MODE-1952 Implement getAllBinaryKeys() on InfinispanBinaryStore

 https://issues.jboss.org/browse/MODE-1952

I also took the liberty to revise the InfinispanUtils#getAllKeys method now that ISPN-2192 (Allow using Distributed Execution against any cache (not just clustered caches)) [1] is resolved. It's possible to further simplify it to use submitEverywhere in a shared cache loader configuration, but it's not clear from the distributed execution documentation if Infinispan will handle it intelligently or not. 


[1] https://issues.jboss.org/browse/ISPN-2192