[HUDI-4018][HUDI-4027] Adding integ test yamls for immutable use-cases. Added delete partition support to integ tests (#5501)

- Added pure immutable test yamls to integ test framework. Added SparkBulkInsertNode as part of it.
- Added delete_partition support to integ test framework using spark-datasource.
- Added a single yaml to test all non core write operations (insert overwrite, insert overwrite table and delete partitions)
- Added tests for 4 concurrent spark datasource writers (multi-writer tests).
- Fixed readme w/ sample commands for multi-writer.

docker/demo/config/test-suite/spark-immutable-dataset.yaml

@@ -0,0 +1,53 @@
+# 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.
+dag_name: spark-immutable-dataset.yaml
+dag_rounds: 5
+dag_intermittent_delay_mins: 0
+dag_content:
+  first_bulk_insert:
+    config:
+      record_size: 200
+      num_partitions_insert: 10
+      repeat_count: 5
+      num_records_insert: 5000
+    type: SparkBulkInsertNode
+    deps: none
+  first_validate:
+    config:
+      validate_hive: false
+      delete_input_data: false
+    type: ValidateDatasetNode
+    deps: first_bulk_insert
+  first_insert:
+    config:
+      record_size: 200
+      num_partitions_insert: 10
+      repeat_count: 5
+      num_records_insert: 5000
+    type: SparkInsertNode
+    deps: first_validate
+  second_validate:
+    config:
+      validate_hive: false
+      delete_input_data: false
+    type: ValidateDatasetNode
+    deps: first_insert
+  last_validate:
+    config:
+      execute_itr_count: 5
+      delete_input_data: true
+    type: ValidateAsyncOperations
+    deps: second_validate