[SPARK-51463] Add Spark Connect-generated Swift source code

Author: dongjoon-hyun

Sources/SparkConnect/base.grpc.swift

@@ -0,0 +1,26 @@
+//
+// 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.
+
+// DO NOT EDIT.
+// swift-format-ignore-file
+//
+// Generated by the gRPC Swift generator plugin for the protocol buffer compiler.
+// Source: spark/connect/catalog.proto
+//
+// For information on using the generated types, please see the documentation:
+//   https://github.com/grpc/grpc-swift
+
+// This file contained no services.