KeyError when using Rule keyword with step data tables or DocStrings

# Bug Report:

## Environment
- **OS**: Windows
- **Python version**: 3.12.10
- **behave version**: 1.3.1
- **allure-behave version**: 2.15.2
- **allure-commons version**: (auto-installed with allure-behave)
- **allure commandline version**: 2.35.1

## Description
When using the `Rule` keyword (introduced in Behave 1.2.6) in feature files, `allure-behave` formatter throws a `KeyError: None` exception when processing steps that contain:
1. Data tables (tables attached to steps)
2. DocStrings (multi-line text enclosed in triple quotes `"""`)

## Expected Behavior
The Allure formatter should successfully process scenarios under a `Rule` that contain steps with data tables or DocStrings, just as it does for scenarios without the `Rule` keyword.

## Actual Behavior
The formatter crashes with a `KeyError: None` traceback when attempting to attach step data (tables or text) to the Allure report.

## Steps to Reproduce

### 1. Create a feature file with Rule and data table
**File: `test/features/simple/tutorial.feature`**
```gherkin
Feature: showing off behave

Rule: Basic arithmetic operations

Scenario: Passing a table as a data through step
Given we have behave installed
When we pass a table as a data through step
| number1 | number2 | result |
| 2 | 3 | 5 |
| 4 | 5 | 9 |
Then behave should be able to read the table
```

### 2. Create step definitions
**File: `test/steps/steps_tutorial.py`**
```python
from behave import given, when, then

@given('we have behave installed')
def step_impl(context):
pass

@when('we pass a table as a data through step')
def step_impl(context):
assert context.table

@then('behave should be able to read the table')
def step_impl(context):
pass
```

### 3. Run with Allure formatter
```bash
behave -f allure_behave.formatter:AllureFormatter -o allure_result_folder
```

### 4. Observe the error
```
Exception KeyError: None
Traceback (most recent call last):
...
File "allure_behave/listener.py", line 147, in start_behave_step
self.logger.attach_data(uuid4(), step_table(step), name='.table', attachment_type=AttachmentType.CSV)
File "allure_commons/reporter.py", line 163, in attach_data
file_name = self._attach(uuid, name=name, attachment_type=attachment_type,
File "allure_commons/reporter.py", line 153, in _attach
self._items[last_uuid].attachments.append(attachment)
File "allure_commons/reporter.py", line 33, in __getitem__
return self.thread_context.__getitem__(item)
KeyError: None
```

## Additional Testing

### Works ✅
- Simple scenarios under `Rule` (no tables/DocStrings)
- Scenario Outlines with Examples tables under `Rule`
- All scenario types WITHOUT `Rule` keyword

### Fails ❌
- Steps with data tables under `Rule`
- Steps with DocStrings under `Rule`

### Test Results Matrix

| Scenario Type | Without Rule | With Rule |
|--------------|--------------|-----------|
| Simple scenario | ✅ Works | ✅ Works |
| Scenario Outline with Examples | ✅ Works | ✅ Works |
| Step with data table | ✅ Works | ❌ **Fails** |
| Step with DocString | ✅ Works | ❌ **Fails** |

## Root Cause Analysis
The issue appears to be in `allure_behave/listener.py` at line 147 (data tables) and line 144 (DocStrings). When processing scenarios under a `Rule`, the `last_uuid` is `None`, causing the attachment operation to fail when trying to access `self._items[last_uuid]`.

The `Rule` hierarchy creates a different context structure that the formatter doesn't handle correctly when attaching step data.

## Suggested Fix
The `start_behave_step` method in `allure_behave/listener.py` needs to properly handle the context hierarchy when scenarios are nested under a `Rule`. The `last_uuid` should be correctly resolved even when scenarios are children of a `Rule` element.

## Additional Context
- The `Rule` keyword is a valid Gherkin construct for organizing scenarios
- Behave 1.2.6+ fully supports the `Rule` keyword
- This issue prevents using Allure reporting with modern Gherkin best practices

## References
- Gherkin Rule keyword documentation: https://cucumber.io/docs/gherkin/reference/#rule
- Behave changelog (Rule support): https://github.com/behave/behave/blob/main/CHANGES.rst

Commencez dans allure_behave/listener.py, autour des lignes 144-147, puis reproduisez le problème avec test/features/simple/tutorial.feature et test/steps/steps_tutorial.py. Exécutez la commande fournie de Behave Allure formatter et vérifiez que les étapes avec des tables et des DocStrings sous une Rule se terminent correctement sans générer de KeyError et produisent leurs pièces jointes.

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