additional mouse event handlers are not invoked

[jf---]

when adding a mouse callback, to viewer.eventsmanager.mouse_events no event would be emitted to the additional callback that handles the signal emitted.

in events.py

    def delegate_mousepress(self, event: QMouseEvent):
        self.viewer.mouse.last_pos = event.pos()
        for mouseevent in self.mouse_events:
            if mouseevent == event:
                print("mousevent: ", mouseevent.title)
                mouseevent.triggered.emit(event)
                mouseevent.is_active = True
                #break

the break blocks emitting to multiple handlers.
I don't think there's any reason to have it, since events are already filtered (mouseevent==event) which is a nice mechanism.