Fix broken unit tests introduced in 0.5.6 (#187)

Author: peter-quix

src/CsharpClient/QuixStreams.State/ScalarState.cs

@@ -328,7 +328,9 @@ public void Clear()
         /// <returns>Returns the value</returns>
         public T Value
         {
-            get => genericConverter(this.inMemoryValue);
+            get => this.inMemoryValue == null
+                ? default 
+                : genericConverter(this.inMemoryValue);
             set => this.inMemoryValue = stateValueConverter(value);
         }
 

src/CsharpClient/QuixStreams.Telemetry.UnitTests/Models/Telemetry/CodecRegistryShould.cs

@@ -42,7 +42,7 @@ public void Register_CompactJsonForBetterPerformance_ShouldRegisterAsExpected()
             var codecs = Transport.Registry.CodecRegistry.RetrieveCodecs(new ModelKey("TimeseriesData"));
             codecs.Count().Should().Be(3);
             codecs.Should().Contain(x => x is TimeseriesDataReadableCodec); // for reading
-            codecs.Should().Contain(x => x is TimeseriesDataJsonCodec); // for reading
+            codecs.Should().Contain(x => x is DefaultJsonCodec<TimeseriesDataRaw>); // for reading
             codecs.Should().Contain(x => x is TimeseriesDataProtobufCodec); // for reading
             codecs.First().GetType().Should().Be(typeof(TimeseriesDataReadableCodec)); // for writing
         }
@@ -57,9 +57,9 @@ public void Register_JsonTimeseriesData_ShouldRegisterAsExpected()
             var codecs = Transport.Registry.CodecRegistry.RetrieveCodecs(new ModelKey("TimeseriesData"));
             codecs.Count().Should().Be(3);
             codecs.Should().Contain(x => x is TimeseriesDataReadableCodec); // for reading
-            codecs.Should().Contain(x => x is TimeseriesDataJsonCodec); // for reading
+            codecs.Should().Contain(x => x is DefaultJsonCodec<TimeseriesDataRaw>); // for reading
             codecs.Should().Contain(x => x is TimeseriesDataProtobufCodec); // for reading
-            codecs.First().GetType().Should().Be(typeof(TimeseriesDataJsonCodec)); // for writing
+            codecs.First().GetType().Should().Be(typeof(DefaultJsonCodec<TimeseriesDataRaw>)); // for writing
         }
 
         [Fact]