Fix the aidge_cmp feature

Context

#39 (closed) : The aidge_cmp feature does not work anymore.

TODO

This MR aims to Adapt the aidge_cmp feature to the recent changes (AdaptToBackend) :

• Generate a json holding information about the intermediate tensors instead of using the log_output function;
• Export the intermediate tensors to be used a references using the generated json;
• Update the aidge_cmp and save_outputs export funtions so that they can handle different data formats;
• Handle fp32 dtype with aidge_cmp feature.