Enable overriding the DEFAULT_AUTORATER_MODEL_NAME

[geromegrignon]

Description

DEFAULT_AUTORATER_MODEL_NAME can't be overridden currently.

Solutions

• Use the model name arvg option by default (so either the DEFAULT_MODEL_NAME, either the overriden one)
• add a dedicated arvg option to override it individually

I can work on a pull request if such a contribution is welcomed.

[devversion]

A dedicated option sounds good to me. I'd be happy to review a PR

[geromegrignon]

Great, working on it.