Factory for ElasticSearch data context of native type.
The factory will activate when DataContext type is specified as
"elasticsearch", "es-node", "elasticsearch-node", "es-transport",
"elasticsearch-transport".
This factory is configured with the following properties:
- clientType (needed if datacontext type is just "elasticsearch" - must be
either "transport" or "node")
- hostname (if clientType is "transport")
- port (if clientType is "transport")
- database (index name)
- cluster
- username (optional, only available if clientType is "transport")
- password (optional, only available if clientType is "transport")
- ssl (optional, only available if clientType is "transport")
- keystorePath (optional, only available if clientType is "transport")
- keystorePassword (optional, only available if clientType is "transport")