How to add an icon?
An Icon can be added to the gui by adding example_icon.svg icon to icons.qrc file and locating in the icon in the icons folder:
<file>icons/example_icon.svg</file>
Afterwards the icons_rc.py has to be recompiled using the following command line:
pyside6-rcc ./GHEtool/gui/icons.qrc -o ./GHEtool/gui/icons_rc.py
Now the icon can be used in the GUI.