Provide a custom repr for function params in `@step` decorator

I have a function like:
```
@step
def foo(x: np.ndarray, y: Dict[str, np.ndarray]): ...
```
It is marked with `@step` decorator and my problem is that the output in the allure repo is too large. I see that the special case of `represnet` is here https://github.com/allure-framework/allure-python/blob/3c74fd540021f776be7b52f8078c9d34eee5c3b6/allure-python-commons/src/utils.py#L167

So I was wondering how to handle other objects like `np.ndarray` or `Dict[str, np.ndarray]`?

One way is to subclass `dict` and give a nice `repr` to it, but what with a single numpy array?Sublassing it just so it got a better `repr` for allure looks... excessive?

Can `@step` accept an additional argument that will explicitly tell it hot to handle `obj -> str` representation?

#### I'm submitting a ...
- [x ] feature request

#### What is the current behavior?

A long text output in the allure report for types like `np.ndarray` or `Dict[str, np.ndarray]` that have long `repr`.

#### What is the expected behavior?

Make `@step` that receives explicit formatter so I can write:

```
def _my_repr(x: np.ndarray, y: Dict[str, np.ndarray]):
return format_1(x), format_2(t) # <-- custom formatting code here

@step(formatter=_my_repr)
def foo(x: np.ndarray, y: Dict[str, np.ndarray]): ...
```

#### Please tell us about your environment:

allure-pytest==2.9.45
allure-python-commons==2.9.45
pytest==6.2.5

#### Other information

I am willing on implementing that feature conditional on the fact there is a way of accepting that change to the mainstream. Will you accept a PR that parametrize `@step` in such a way?

Commencez par la logique de représentation des cas particuliers dans allure-python-commons/src/utils.py et suivez la manière dont @step collecte les paramètres des fonctions. Définissez comment un formatter explicite doit être accepté et appliqué aux paramètres, puis vérifiez que les tableaux numpy et les dictionnaires produisent la sortie compacte demandée sans modifier le comportement par défaut.

Rédigé par le modèle d'indexation à partir du texte de l'issue.