[HUDI-1468] Support custom clustering strategies and preserve commit metadata as part of clustering (#3419)

Co-authored-by: Satish Kotha <satishkotha@uber.com>

hudi-common/src/main/avro/HoodieClusteringPlan.avsc

@@ -45,6 +45,11 @@
        "name":"version",
        "type":["int", "null"],
        "default": 1
+    },
+   {
+      "name":"preserveHoodieMetadata",
+      "type":["null", "boolean"],
+      "default": null
     }
   ]
 }