GitLab

* fix on --task list

* add fixes to tokeniation

* differentiate encoding for seq2seq and decoder

* return token setting

* format for pre-commit

* Seq2seq fix, pt2 (#1630)

* getting model class only when defined

* encode_pair handles None, add_special_tokens turned into dict with default value

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Co-authored-by: achervyakov <77295913+artemorloff@users.noreply.github.com>