[MNG-7138] Proper verify of plugin configuration Bean set method call

**[Slawomir Jaranowski](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=slawekjaranowski)** opened **[MNG-7138](https://issues.apache.org/jira/browse/MNG-7138?redirect=false)** and commented

When we use custom `Bean` as `plugin` parameter configuration, `set` method of `Bean` is only called for default value.

Example:

```java
public class MyMojo extends AbstractMojo
{
@Parameter
private Bean beanParam;
}
```

```java
public class Bean
{
private String field1;
private String field2;

public void set(String value) {
this.field1 = value;
}
}
```

 
And configuration with fields name:

```xml

value1
value2

```

in this case `Bean.set` is not called.

 

When we have:

```xml

value

```

`Bean.set` is called.

 

I will fix it.

---

**Issue Links:**
- [MNG-5013](https://issues.apache.org/jira/browse/MNG-5013) Allow to condense configuration of plugin parameter beans that commonly require only one value

**Remote Links:**
- [GitHub Pull Request #106
](https://github.com/apache/maven-integration-testing/pull/106)