* Added whisper state + default state on the whisper_context
* Fixed some examples and bindings
* Fixed whisper_n_len (which was used in some binding) and added whisper_n_len_from_state
* Fixed comments
* whisper : reuse kv_cache_free() and fix compiler warnings
* whisper : clean-up the API comments
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Co-authored-by: Sandro Hanea <sandrohanea@microsoft.com>
Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>