Update tiny model creation script
# What does this PR do?

Main changes:
- **Better error message**, including allowing to save the traceback to the report files
- Add `UNCONVERTIBLE_MODEL_ARCHITECTURES`, so for those models could not be converted to tiny versions, the code will skip them (and we have cleaner reports)
- Add a method `build_tiny_model_summary`, which will produce the entries we might want to add `tests/utils/tiny_model_summary.json` (for pipeline testing purpose)
  - (well, we might want to remove this file in the future) 
_The documentation is not available anymore as the PR was closed or merged._