MetricPredicate translates to incompatible query in Elasticsearch REST Client

[lorthirk]

Describe the bug
The current implementation of MetricPredicate translate to a query that consider the Datastore Schema. Specifically, an example MetricPredicate would translate to JSON as

{
    "query": {
        "range" : {
            "temperature" : {
                "gte" : 10,
                "lte" : 20,
            }
        }
    }
}

While it should translate to this JSON to support our current schema:

{
    "query": {
        "range" : {
            "metrics.temperature.int" : {
                "gte" : 10,
                "lte" : 20,
            }
        }
    }
}

This means that filtering for a metric type and/or value would always return 0 entries

To Reproduce
Steps to reproduce the behavior:

1. Perform a REST call to /{scopeId}/dataMessages filtering on metricName, metricType, metricMin and metricMax

Expected behavior
A set of results matching the name, type and values would return

Version of Kapua
1.0.9
1.1.2

Type of deployment
[x] Local Vagrant deployment
[x] Docker
[x] Openshift (in its variants)
[x] Others

Main component affected
[ ] Console (in case of console please report info on which browser you encountered the problem)
[x] REST API
[ ] Message Broker
[x] - Others

Additional context
Basically any component that uses di ES REST client is affected