[HUDI-1338] Adding Delete support to test suite framework (#2172)

- Adding Delete support to test suite. 
         Added DeleteNode 
         Added support to generate delete records

docker/demo/config/test-suite/source.avsc

@@ -46,6 +46,10 @@
   }, {
     "name" : "fare",
     "type" : "double"
-  } ]
+  }, {
+   "name" : "_hoodie_is_deleted",
+   "type" : "boolean",
+    "default" : false
+  }]
 }