modular_model_converter bugfix on assignments (#35642)
* added bugfix in modular converter to keep modular assignments for docstrings, expected outputs etc.
* revert stracoder2 docstring copying, add forward in EMU3 to enable docstring assingment, remove verbatim assignments in modular converter
* added _FOR_DOC in assignments to keep, corrected wrong checkpoint name in ijepa's configuration
