[BUG] PySide6 attributes

[malik-irain]

Same issue as pymodaq and pymodaq_gui with attributes only accessible at the class level and not object level

  File "/home/mairain/original-pymodaq/pymodaq_plugin_manager/src/pymodaq_plugin_manager/utils.py", line 72, in drawPrimitive
    if element == self.PE_IndicatorItemViewItemDrop and not option.rect.isNull():
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'MyStyle' object has no attribute 'PE_IndicatorItemViewItemDrop'