26665: Toolbar buttons do not react to long clicks

[krasko78]

Resolves: #26665

This is the same issue as #16012. The fix done there appears not to have fixed it. Handling the pressAndHold signal, even directly as implemented in the fix, suppresses the click signal.

I have found a new fix: when handling the pressAndHold signal, if we do not consume it, we should set the accepted property of the mouse event to false. In this case the click event will not be suppressed. Interestingly, for pressAndHold the accepted property is true by default which means the event has to be unaccepted if not consumed. So I am reverting the fix for #16012 and am taking care of the accepted property: in FlatButton I set accepted to false to not suppress the click signal if there are no handlers or none consumes the event. On the other hand, when pressAndHold is consumed in NoteInputBar and StyledToolBarItem, accepted will be set to true.

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