As requested by Angelo Fuchs, I post this as an answer though it doesn't contain an app recommendation:
Having done a pretty thorough search (while updating my list of apps for notification manipulation along) I'm pretty sure that such an app does not exist. My research not only included several major market platforms (Google, F-Droid, Aptoide), but also the Xposed repository.
Though we usually say that "I haven't found" does not equal "it doesn't exist" (even not with the limitation of "yet"): I guess I can consider myself quite familiar with what kind of Android apps are around (with few exceptions like games or asocial networking (Facebook & Co.)) – which at least makes it highly unlikely for such an app having slipped through my nets. The closest you can get to this is setting "silent times", when all notifications are suppressed – or limit how often an app is permitted to notify you in a given timeframe; examples for both can be found in above linked list.
I gladly stand corrected and remove my answer if someone can prove otherwise, of course.