Hufnagel update feature request: add an `Untoggle All Ligated Neumes` button to the "MEI Actions" dropdown menu

The Neon editing page has an "MEI Actions" dropdown menu that includes such handy buttons as `Untoggle Invalid Obliques` and `Untoggle All Syllables`. Perhaps I'm being overly pessimistic, but I can imagine a future where a user uploads an MEI file where a majority of the clives are incorrect. In this scenario, it may save them time to just untoggle all of them at once, to change pitches faster.