adding indexed created_at column to lineage events table

Author: prachim-collab

api/src/main/resources/marquez/db/migration/V52__lineage_events_created_at_indexed.sql

@@ -0,0 +1,4 @@
+ALTER TABLE lineage_events ADD created_at TIMESTAMP;
+
+create index lineage_events_created_at_index
+    on lineage_events (created_at desc);