Add support for {this} in step names

If this pull request is merged this will work:

```java
class SomeClass {
    @Step("Do something with {this}")
    public void doSomething() {
        // ...
    }

    public String toString() {
        // ...
    }
}
```
I copy-pasted one of the other tests in AllureAspectUtilsTest.java. There are russian comments in all of them.