ENG-60: Move and hide additional fermatas

When a fermata in a secondary voice is read, this commit adds handling
that moves it below the staff. Additionally, there is handling to hide
it if the duration of both voices is the same, or if there is also
already a fermata below the staff.

Duplicate of musescore#8509

importexport/musicxml/importmxmlpass2.cpp

@@ -1029,6 +1029,28 @@ static void addFermataToChord(const Notation& notation, ChordRest* cr)
             cr->el().push_back(na);       // store for later move to segment
       else
             cr->segment()->add(na);
+
+      // Move or hide fermata based on existing fermatas.
+      bool alreadyAbove = false;
+      bool alreadyBelow = false;
+      for (Element* e: cr->segment()->annotations()) {
+            if (e->isFermata() && e != na
+            && e->staffIdx() == na->staffIdx() && e->track() != na->track()) {
+                  Element* otherCr = cr->segment()->elist()[e->track()];
+                  if (toFermata(e)->placement() == Placement::BELOW) alreadyBelow = true;
+                  if (toFermata(e)->placement() == Placement::ABOVE) alreadyAbove = true;
+
+                  if (direction.isEmpty() && alreadyAbove)
+                        na->setPlacement(Placement::BELOW);
+                  else if (direction.isEmpty() && alreadyBelow)
+                        na->setPlacement(Placement::ABOVE);
+
+                  if ((otherCr->isChord() && cr->isChord()
+                  && toChord(otherCr)->durationType() == toChord(cr)->durationType())
+                  || (alreadyAbove && alreadyBelow))
+                        na->setVisible(false);
+                  }
+            }     
       }
 
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