[Swift] Moves grpc example to grpc/examples (#6479)

Updates generated Code

Removes grpc generation code from tests dir

Small fix to generate.sh

grpc/examples/swift/Greeter/Package.swift

@@ -0,0 +1,58 @@
+// swift-tools-version:5.1
+/*
+ * Copyright 2020 Google Inc. All rights reserved.
+ *
+ * Licensed 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.
+ */
+
+import PackageDescription
+
+let package = Package(
+  name: "Greeter",
+  platforms: [
+    .iOS(.v11),
+    .macOS(.v10_14),
+  ],
+  dependencies: [
+    .package(path: "../../../../swift"),
+    .package(url: "https://github.com/grpc/grpc-swift.git", .exact("1.0.0-alpha.24")),
+  ],
+  targets: [
+    // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+    // Targets can depend on other targets in this package, and on products in packages which this package depends on.
+    .target(
+      name: "Model",
+      dependencies: [
+        "GRPC",
+        "FlatBuffers",
+      ],
+      path: "Sources/Model"),
+
+    // Client for the Greeter example
+    .target(
+      name: "Client",
+      dependencies: [
+        "GRPC",
+        "Model",
+      ],
+      path: "Sources/client"),
+
+    // Server for the Greeter example
+    .target(
+      name: "Server",
+      dependencies: [
+        "GRPC",
+        "Model",
+      ],
+      path: "Sources/server"),
+  ])