AsyncAPI Schema object deserializer is missing some properties

### Describe the bug
Schema deserializer `AsyncApiSchemaDeserializer.cs` is missing some fixed fields compared to the [AsyncAPI specification](https://www.asyncapi.com/docs/reference/specification/v2.0.0#schemaObject).

In particular:
```
patternProperties 
additionalItems 
propertyNames
```

### Additional context
Similar PR's touching the same code #120 and #121 
