AutoML doesn't use the default namespace of the project

**System Information (please complete the following information):**
- Model Builder Version (available in Manage Extensions dialog): 17.19.2.2511501
- Visual Studio Version : 17.14.9

**Describe the bug**
- On which step of the process did you run into an issue: Train/Evaluate
- Clear description of the problem:
When generating classes, AutoML doens't use the default namespace of the project, but uses the name of the project and replace the dots with underscore

**To Reproduce**
Steps to reproduce the behavior:
1. Create a new model, specify the data and train the model
2. Click on next, it will generate the classes for the model and asks for a reload of the project
3. The classes generated contain the wrong namespace

**Expected behavior**
Expected behaviour is to use the default namespace as defined in the project properties

**Additional context**
Not a blocking issue, just a cohesive thing. By default, in .Net, namespaces don't contain underscores, they contain dots. And if we want to extend the generated classes, we can create our own file to add additionnal properties/methods (thanks to the usage of partial classes) to our model. But the namespace in that file is the default namespace, whereas the generated classes by AutoML is not.

Inizia tracciando il passaggio di generazione delle classi di AutoML dopo Train/Evaluate e confronta il namespace generato con il namespace predefinito del progetto ricavato dalle proprietà del progetto. Riproduci il workflow indicato e ispeziona le classi generate. Il lavoro è concluso quando usano il namespace predefinito del progetto con i punti e rimangono compatibili con le estensioni parziali.

Scritto dal modello di indicizzazione a partire dal testo della issue.