BUG: Fix localization and inconsistent state in ctkModalityWidget

[lassoan]

There were several issues with the imaging modality selector widget (ctkModalityWidget):

• when imaging modality abbreviations (CT, MRI, XA, ...) were localized then the widget did not work at all, because the checkbox text was used to identify the checkboxes
• widget state was stored redundantly in SelectedModalities and VisibleModalities variables and the checkbox properties; and these were often inconsistent

Fixed by using Qt object names to identify checkboxes; and removing SelectedModalities and VisibleModalities variables (store widget state in the checkbox properties).

[jcfr]

Since I plan on finalizing #1005, let's fix the build-qt4 CI.

I target to wrap this up by end of next week, then we will tag CTK and move forward with removing Qt4 support and adding support for Qt6.

[jcfr]

Should this file be updated ? See https://github.com/commontk/CTK/blob/master/Libs/Widgets/Testing/Cpp/ctkModalityWidgetEventTranslatorPlayerTest1.xml

[jcfr]

re: Qt Testing

Once we are done with Qt4 removal, we should evaluate if the overall of maintaining QtTesting player/translator for both CTK & Slicer is worth it.

[lassoan]

Not using QSignalBlocker leads to lower-quality code and extra development effort, so this is a little bit annoying, but OK, let's do this one last time.

Once we are done with Qt4 removal, we should evaluate if the overall of maintaining QtTesting player/translator for both CTK & Slicer is worth it.

We are looking into refreshing/improving QtTesting for recording tutorials that can be replayed in different languages (because we cannot use English language screenshots in non-English tutorials). We would like to generate executable Python code instead of XML. Maybe we'll use the recorder (just fix and extend it as needed) and convert the XML to Python; or maybe we'll change it more significantly to create Python code directly.

Should this file be updated ? See https://github.com/commontk/CTK/blob/master/Libs/Widgets/Testing/Cpp/ctkModalityWidgetEventTranslatorPlayerTest1.xml

The test still passes.

[jcfr]

QSignalBlocker

So that the cleaned up code uses QSignalBlocker, I suggest ...

#if QT_VERSION >= QT_VERSION_CHECK(5,3,0)
  QSignalBlocker blocker(this->AnyCheckBox);
#else
  bool wasBlocking = this->AnyCheckBox->blockSignals(false);
#endif

...

#if QT_VERSION < QT_VERSION_CHECK(5,3,0)
    this->blockSignals(wasBlocking)
    return;
#endif