[Whisper] Refactor forced_decoder_ids & prompt ids (#28687)
* up
* Fix more
* Correct more
* Fix more tests
* fix fast tests
* Fix more
* fix more
* push all files
* finish all
* make style
* Fix timestamp wrap
* make style
* make style
* up
* up
* up
* Fix lang detection behavior
* Fix lang detection behavior
* Add lang detection test
* Fix lang detection behavior
* make style
* Update src/transformers/models/whisper/generation_whisper.py
Co-authored-by: Sanchit Gandhi <93869735+sanchit-gandhi@users.noreply.github.com>
* better error message
* make style tests
* add warning
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Co-authored-by: Sanchit Gandhi <93869735+sanchit-gandhi@users.noreply.github.com>