[FT] Align parameter names in config files and config classes

[albertvillanova]

Issue encountered

Currently, the example config files have a parameter named dtype.

When parsing the config file into the config class, this parameter is renamed to model_dtype.

Solution/Feature

Align the name to model_dtype in both config files and config classes.

Context:

In the config files

• it already exists a model parameter called model_name
• there are also instance parameters called instance_type and instance_size

This was discussed in:

• Test inference endpoint model config parsing from path #434

Possible alternatives

Leave it as it is.

[clefourrier]

That works for me if you want to homogeneize the code across the models for this :)