PLT-7705: API to get data retention policy. (#7539)

* PLT-7705: API to get data retention policy.

* Fix review comments.

i18n/en.json

@@ -3687,6 +3687,10 @@
     "id": "ent.compliance.run_started.info",
     "translation": "Compliance export started for job '{{.JobName}}' at '{{.FilePath}}'"
   },
+  {
+    "id": "ent.data_retention.generic.license.error",
+    "translation": "License does not support Data Retention."
+  },
   {
     "id": "ent.elasticsearch.aggregator_worker.create_index_job.error",
     "translation": "Elasticsearch aggregator worker failed to create the indexing job"