Support T5 Generation (#3228)
* fix conflicts
* update bart max length test
* correct spelling mistakes
* implemented model specific encode function
* fix merge conflicts
* better naming
* save intermediate state -> need to rethink strucuture a bit
* leave tf problem as it is for now
* current version
* add layers.pop
* remove ipdb
* make style
* clean return cut decoding
* remove ipdbs
* Fix restoring layers in the decoders that doesnt exists.
* push good intermediate solution for now
* fix conflicts
* always good to refuse to merge conflicts when rebasing
* fix small bug
* improve function calls
* remove unused file
* add correct scope behavior for t5_generate
Co-authored-by: Morgan Funtowicz <funtowiczmo@gmail.com>
