Add warning for missing attention mask when pad tokens are detected (#25345)
* Add attention mask and pad token warning to many of the models
* Remove changes under examples/research_projects
These files are not maintained by HG.
* Skip the warning check during torch.fx or JIT tracing
* Switch ordering for the warning and input shape assignment
This ordering is a little cleaner for some of the cases.
* Add missing line break in one of the files