ISPN-3487 Missing protobuf fields sould be indexed with their declared d...

...efault value (if any) instead of being indexed as null

Also fixes ISPN-3488

* Refactor MessageContext to reuse the similar class already present in protostream lib
* Upgrade to a newer protostream that has less unwanted dependecies
* Also make remote-query related dependecies optional in HotRod client
* Add test for remote queries on top of Infinispan Directory provider

Jira: https://issues.jboss.org/browse/ISPN-3487 ,
https://issues.jboss.org/browse/ISPN-3488

Please integrate in master.