Suggestion: Add Optional "Advanced Settings" Section in Model Builder

Model Builder is a great tool for building machine learning models without writing code. However, I think its potential is underutilized by not offering a section for more advanced users who want greater control over the training process.

**Proposal:**

Add an optional and hidden-by-default section called "Advanced Settings" or "Expert Mode", which includes the ability to:

- Manually choose the training algorithm.
- Edit key hyperparameters (e.g., number of trees, learning rate, number of epochs, etc.).
- Customize the data preparation pipeline (e.g., normalization, encoding, cleaning).
- Set limits for time or resources used during AutoML.
- Display more detailed evaluation metrics (e.g., confusion matrix, ROC curve, etc.).

**Why this matters:**

This would allow developers with more experience or technical curiosity to get more out of ML.NET without having to abandon Model Builder or rewrite the generated code.

**Benefits:**

- Keeps things simple for beginners.
- Unlocks more flexibility for intermediate and advanced users.
- Extends the usefulness and lifecycle of Model Builder within Visual Studio.

Thanks for the great work! I believe this feature could make Model Builder even more powerful and appealing to a broader audience.

L’issue nomina Model Builder, ma non indica file, test o punti di ingresso. Inizia mappando la UI di Model Builder e il flusso di configurazione dell’addestramento, quindi chiarisci quali controlli proposti rientrano nell’ambito e come verranno convalidati il comportamento nascosto per impostazione predefinita e le metriche di valutazione dettagliate.

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