Always sort the Default/fallback profile first

As suggested by Kurt in
https://invent.kde.org/utilities/konsole/-/merge_requests/351

src/profile/ProfileManager.cpp

@@ -39,6 +39,13 @@ static bool profileIndexLessThan(const Profile::Ptr& p1, const Profile::Ptr& p2)
 
 static bool profileNameLessThan(const Profile::Ptr& p1, const Profile::Ptr& p2)
 {
+    // Always put the Default/fallback profile at the top
+    if (p1->isFallback()) {
+        return true;
+    } else if (p2->isFallback()) {
+        return false;
+    }
+
     return QString::localeAwareCompare(p1->name(), p2->name()) < 0;
 }