Changes from 4141e00ae68cb27fd85a630bf6a5ec28516b0251
* get_midi_programs, remove_duplicated_notes, detect_chords, merge_tracks, merge_same_program_tracks and current_bar_pos methods have been moved from miditok/midi_tokenizer_base.py to miditok/utils.py, you can call them with **miditok.utils.the_method()**
* New method merge_tracks_per_class which allows to merge tracks of a MIDI of the same instrument class
* MIDI_INSTRUMENTS pitch range value changed from tuple to range
* INSTRUMENT_CLASSES changed from type Dict[int: Tuple[int, str]] to List[Dict[str: Union[str, range]]] so its fits the format of other constants. The index of the list corresponds to the index of each class.
* INSTRUMENT_CLASSES_RANGES replaced by CLASS_OF_INST to easily gets the class of any instrument / track by its program
* Minor cleans in imports
Compatibility
* See first point above if you used utils functions
* See above if you used MIDI_INSTRUMENTS, INSTRUMENT_CLASSES and INSTRUMENT_CLASSES_RANGES constants