[HUDI-242] Support for RFC-12/Bootstrapping of external datasets to hudi (#1876)

- [HUDI-418] Bootstrap Index Implementation using HFile with unit-test
 - [HUDI-421] FileSystem View Changes to support Bootstrap with unit-tests
 - [HUDI-424] Implement Query Side Integration for querying tables containing bootstrap file slices
 - [HUDI-423] Implement upsert functionality for handling updates to these bootstrap file slices
 - [HUDI-421] Bootstrap Write Client with tests
 - [HUDI-425] Added HoodieDeltaStreamer support
 - [HUDI-899] Add a knob to change partition-path style while performing metadata bootstrap
 - [HUDI-900] Metadata Bootstrap Key Generator needs to handle complex keys correctly
 - [HUDI-424] Simplify Record reader implementation
 - [HUDI-423] Implement upsert functionality for handling updates to these bootstrap file slices
 - [HUDI-420] Hoodie Demo working with hive and sparkSQL. Also, Hoodie CLI working with bootstrap tables

Co-authored-by: Mehrotra <uditme@amazon.com>
Co-authored-by: Vinoth Chandar <vinoth@apache.org>
Co-authored-by: Balaji Varadarajan <varadarb@uber.com>

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

@@ -0,0 +1,44 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+{
+   "namespace":"org.apache.hudi.avro.model",
+   "type":"record",
+   "name":"HoodieBootstrapIndexInfo",
+   "fields":[
+      {
+        "name":"version",
+        "type":["int", "null"],
+        "default": 1
+      },
+      {
+        "name":"bootstrapBasePath",
+        "type":["null", "string"],
+        "default" : null
+      },
+      {
+        "name":"createdTimestamp",
+        "type":["null", "long"],
+        "default" : null
+      },
+      {
+        "name":"numKeys",
+        "type":["null", "int"],
+        "default" : null
+      }
+   ]
+}