Move to ElasticSearch 7

Add initial support for project ordering
Add support for sortable task duration (used by the UI in the experiment's table)
Add support for project name in worker's current task info
Add support for results and artifacts in pre-populates examples
Add demo server features

server/bll/queue/queue_metrics.py

@@ -18,7 +18,6 @@ log = config.logger(__file__)
 
 class QueueMetrics:
     class EsKeys:
-        DOC_TYPE = "metrics"
         WAITING_TIME_FIELD = "average_waiting_time"
         QUEUE_LENGTH_FIELD = "queue_length"
         TIMESTAMP_FIELD = "timestamp"
@@ -66,7 +65,6 @@ class QueueMetrics:
             entries = [e for e in queue.entries if e.added]
             return dict(
                 _index=es_index,
-                _type=self.EsKeys.DOC_TYPE,
                 _source={
                     self.EsKeys.TIMESTAMP_FIELD: timestamp,
                     self.EsKeys.QUEUE_FIELD: queue.id,
@@ -93,7 +91,6 @@ class QueueMetrics:
     def _search_company_metrics(self, company_id: str, es_req: dict) -> dict:
         return self.es.search(
             index=f"{self._queue_metrics_prefix_for_company(company_id)}*",
-            doc_type=self.EsKeys.DOC_TYPE,
             body=es_req,
         )
 
@@ -109,7 +106,7 @@ class QueueMetrics:
             "dates": {
                 "date_histogram": {
                     "field": cls.EsKeys.TIMESTAMP_FIELD,
-                    "interval": f"{interval}s",
+                    "fixed_interval": f"{interval}s",
                     "min_doc_count": 1,
                 },
                 "aggs": {