model-conversion : add warn about transformers mismatch (#18691)

model-conversion : add warn about transformers mismatch (#18691)

This commit adds a check comparing the installed transformers library
with the transformers version that the original model supports. This
check will be performed upon a model verification failure and prints a
warning/hint to the user suggesting to install the correct version of
the transformers library.

The motivation for this change is that it is possible for the model
verification to fail due to differences in the transformers library used
and it might not be obvious that this could be the cause of the failure.
With this warning the correct version can be checked and hopefully save
time troubleshooting the cause of the verification failure.