chore(Client.Examples): add cloud worker example

Client.Examples/CloudWorkerExample.cs.md

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+## Camunda Cloud Worker Example
+In the following you see an example of how to use the Zeebe C# client job worker with the CamundaCloud.
+
+We have a separate thread which outputs how many jobs with worker has completed in a second.
+With that we can play around with the different job worker configuration and see how it affects the throughput.
+
+```csharp
+using System;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using NLog;
+using NLog.Extensions.Logging;
+using Zeebe.Client;
+using Zeebe.Client.Api.Responses;
+using Zeebe.Client.Api.Worker;
+using Zeebe.Client.Impl.Builder;
+
+namespace Client.Examples
+{
+    internal class CloudWorkerExample
+    {
+        private const string AuthServer = "https://login.cloud.ultrawombat.com/oauth/token";
+        private const string ClientId = "{clientId}";
+        private const string ClientSecret = "{clientSecret}";
+        private const string Audience = "{cluster-id}.zeebe.ultrawombat.com";
+        private const string ZeebeUrl = Audience + ":443";
+
+        private static volatile int lastCompleted;
+        private static volatile int currentCompleted;
+        private static readonly string DemoProcessPath =
+            Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Resources", "ten_tasks.bpmn");
+
+        private static readonly string PayloadPath =
+            Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Resources", "big_payload.json");
+
+        private static readonly string JobType = "benchmark-task";
+        private static readonly string WorkerName = Environment.MachineName;
+
+        private static readonly Logger Logger = LogManager.GetCurrentClassLogger();
+
+        public static async Task Main(string[] args)
+        {
+            // create zeebe client
+            var client = ZeebeClient.Builder()
+                .UseLoggerFactory(new NLogLoggerFactory())
+                .UseGatewayAddress(ZeebeUrl)
+                .UseTransportEncryption()
+                .UseAccessTokenSupplier(
+                    CamundaCloudTokenProvider.Builder()
+                        .UseAuthServer(AuthServer)
+                        .UseClientId(ClientId)
+                        .UseClientSecret(ClientSecret)
+                        .UseAudience(Audience)
+                        .Build())
+                .Build();
+
+            var topology = await client.TopologyRequest().Send();
+
+            Logger.Info(topology.ToString);
+            Console.WriteLine(topology);
+
+            Task.Run(async () =>
+            {
+                while (true)
+                {
+                    await Task.Delay(1000);
+                    Logger.Info("Completed " + (currentCompleted - lastCompleted) + " in the last second.");
+                    lastCompleted = currentCompleted;
+                }
+            });
+
+            // open job worker
+            using (var signal = new EventWaitHandle(false, EventResetMode.AutoReset))
+            {
+                client.NewWorker()
+                    .JobType(JobType)
+                    .Handler(HandleJob)
+                    .MaxJobsActive(120)
+                    .Name(WorkerName)
+                    .AutoCompletion()
+                    .PollInterval(TimeSpan.FromMilliseconds(100))
+                    .Timeout(TimeSpan.FromSeconds(10))
+                    .PollingTimeout(TimeSpan.FromSeconds(30))
+                    .HandlerThreads(8)
+                    .Open();
+
+                // blocks main thread, so that worker can run
+                signal.WaitOne();
+            }
+        }
+
+        private static async Task HandleJob(IJobClient jobClient, IJob job)
+        {
+            await Task.Delay(150);
+            jobClient.NewCompleteJobCommand(job).Send();
+            currentCompleted++;
+        }
+    }
+}
+```