fix #40521: crash on adding text from within note entry mode

While we could simply disallow text entry from within note entry mode as we apparently did for 1.3 (by removing STATE_NOTE_ENTRY from the commands in shortcut.cpp), I think it is nicer for the user to allow the commands but have them kick him out of note entry mode first, like we do with "play".  So that's what I do in this PR.  Chord symbols, lyrics, figured bass, and general text are all affected.