Add support to aliases on Solr Cloud

New functionalities have been added to allow the module to communicate with the information contained in the Solr cluster.

By retrieving this information, the module is able to detect which collections have been configured for an alias and thus run the luke against all of them, retrieving all the fields that exist after an alias.

“This is necessary because Solr by default consumes the schema information of the first collection, skipping the rest.”

The above functionality has been unchanged.