GUI refactoring: move spinbox/combobox/textbox/checkbox creating functions to WidgetUtils

To create spinbox/combobox/textbox/checkbox and link it with corresponding getters and setters of a variable the special functions were used over the code base. Sometimes these functions were duplicated. I moved almost all these "create functions" to the already existing WidgetUtils files.

Class SafeSpinBox was added. It differs from QSpinbox by the possibility to forbid mouse wheel scrolling without getting focus. This feature has already existed for DoubleSpinbox class, but not for integer value spinbox.