Some GUI packages are missing from poetry config file/bug fix

[ivanshilo]

It is not possible to run 'gui_demonstrator.py' after installation since some packages are missing:
Have to call those ones:

• poetry add qtpy
• poetry add pyqt5
• poetry add qimage2ndarray

In addition to that had to fix QtShortCuts.py since slider does not support float values but integers only. Also spinbox type has to processed correctly on setValue (int or float value).

One has to change in class QInputNumber(QInput):

def _doSetValue(self, value):
        v = value
        if self.decimals == 0:
            v = int(value)
        self.spin_box.setValue(v)
        if self.slider is not None:            
            self.slider.setValue(int(value * self.decimal_factor))

[rgerum]

ah yes newer QT versions require the floats cast to ints first. I should fix that.

About the additional dependencies. I am not sure if it would be a good idea to add them not everyone might need them. But I could use an additional group of dependencies.