Refactor proto services. More descriptive names + add packages for ea…

…ch service + helper classes for proto<->pojo conversions

Signed-off-by: Finn Carroll <carrofin@amazon.com>

server/src/main/java/org/opensearch/grpc/services/document/DocumentServiceImpl.java

@@ -0,0 +1,57 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.grpc.services.document;
+
+import io.grpc.stub.StreamObserver;
+import opensearch.proto.BulkRequest;
+import opensearch.proto.BulkResponse;
+import opensearch.proto.CreateOperation;
+import opensearch.proto.DeleteOperation;
+import opensearch.proto.IndexOperation;
+import opensearch.proto.ResponseItem;
+import opensearch.proto.UpdateOperation;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.opensearch.client.node.NodeClient;
+
+import opensearch.proto.services.DocumentServiceGrpc;
+
+public class DocumentServiceImpl extends DocumentServiceGrpc.DocumentServiceImplBase {
+    private static final Logger logger = LogManager.getLogger(DocumentServiceImpl.class);
+    private final NodeClient client;
+
+    public DocumentServiceImpl(NodeClient client) {
+        this.client = client;
+    }
+
+    @Override
+    public void bulk(BulkRequest request, StreamObserver<BulkResponse> responseObserver) {
+        super.bulk(request, responseObserver);
+    }
+
+    @Override
+    public void index(IndexOperation request, StreamObserver<ResponseItem> responseObserver) {
+        super.index(request, responseObserver);
+    }
+
+    @Override
+    public void create(CreateOperation request, StreamObserver<ResponseItem> responseObserver) {
+        super.create(request, responseObserver);
+    }
+
+    @Override
+    public void update(UpdateOperation request, StreamObserver<ResponseItem> responseObserver) {
+        super.update(request, responseObserver);
+    }
+
+    @Override
+    public void delete(DeleteOperation request, StreamObserver<ResponseItem> responseObserver) {
+        super.delete(request, responseObserver);
+    }
+}