Rewrite rule: Remove optional bias

Remove optional bias in conv and other ops when it is all zero.

- Also: Enable more conv fusion rules as default or ort optimization rules.

<img width="754" height="975" alt="Image" src="https://github.com/user-attachments/assets/1b8a5e89-7e92-4280-bcef-845cb7453848" />