Add an attribute to model classes that allows to retrieve the model class name

[LexABzH]

Problem

Each model class has an attribute _default_model_name which is then used to create a model_name attribute.

However, the model_name can be changed by the user, which prevent us to reuse it later to reload a model "from standalone".
We should have class attributes that can't be changed by the user, and this attribute should be save in the configurations file to be reuse later if we need to reload a model from standalone files.

Concerned template

• NLP template
• NUM template
• VISION template
• API template
• How templates are generated - Jinja

Solution

Add a new class attribute to each model class.
Save it in the configuration file.
Use this attribute to reload a model from standalone files.

Additional context

Tests must be updated.