Adding start/end time to data processing-job execution details

For the data processing -> job execution -> details page, we
are adding start/end time for the job execution as details
for the job execution being viewed.

Change-Id: I931c836630f4a7a58f7c0b60161cfca6bbba9ee1
Closes-Bug: bug #1336028
Co-Authored-By: Andrew Lazarev <alazarev@mirantis.com>

openstack_dashboard/dashboards/project/data_processing/job_executions/templates/data_processing.job_executions/_details.html

@@ -16,6 +16,10 @@ <h3>{% trans "Job Execution Overview" %}</h3>
         <dd>{{ job_execution.cluster_id }} ({{ object_names.cluster_name }})</dd>
         <dt>{% trans "Last Updated" %}</dt>
         <dd>{{ job_execution.updated_at }}</dd>
+        <dt>{% trans "Started" %}</dt>
+        <dd>{{ job_execution.start_time }}</dd>
+        <dt>{% trans "Ended" %}</dt>
+        <dd>{{ job_execution.end_time }}</dd>
         <dt>{% trans "Return Code" %}</dt>
         <dd>{{ job_execution.return_code }}</dd>
         <dt>{% trans "Oozie Job Id" %}</dt>