Implement correct part names and abbreviations of instrument change

[hhpmusic]

When there's an instrument change at the middle of the music, Dolet should export corresponding part-name/abbreviation-display tags instead of adding an IC text as word tag. User edited part names and/or abbreviations should be included. If no full name is available, just include an abbreviation. If none of these are given, just include any other info such as transposition (if there is) as Dolet works currently. The user-edited part names should include those done during the staff is hidden.