Add Directory.Build.props. (#2120)

* Add Directory.Build.props.

* Adjust Analysis related properties and add conditional enablement for ContinuousIntegrationBuild.

* Adopt new changes in master

---------

Co-authored-by: christian <6939810+chkr1011@users.noreply.github.com>

Source/MQTTnet.Benchmarks/ReaderExtensionsBenchmark.cs

@@ -13,7 +13,7 @@ namespace MQTTnet.Benchmarks;
 [SimpleJob(RuntimeMoniker.Net60)]
 [RPlotExporter, RankColumn]
 [MemoryDiagnoser]
-public class ReaderExtensionsBenchmark
+public sealed class ReaderExtensionsBenchmark : IDisposable, IAsyncDisposable
 {
     MqttPacketFormatterAdapter _mqttPacketFormatter;
     MemoryStream _stream;
@@ -83,4 +83,17 @@ public class ReaderExtensionsBenchmark
             }
         }
     }
+
+    public void Dispose()
+    {
+        _stream?.Dispose();
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (_stream != null)
+        {
+            await _stream.DisposeAsync();
+        }
+    }
 }