BUG: Fixed incorrect slice view annotations appearing when disabled

- Fixed incorrect scalar bar display (scalar bar shown but not updating when zoom factor changing) and python errors (KeyError: 'Red') when showScalingRulerCheckBox is enabled and showSliceViewAnnotations is disabled
- Initialize the dialog box even if showSliceViewAnnotations is false (otherwise all sections remain enabled until a button is clicked)
- Disable restoreDefaultsButton if showSliceViewAnnotations is false (otherwise it would change disabled options)
- Don't modify showColorScalarBarCheckBox and showScalingRulerCheckBox states when only the showSliceViewAnnotations is changed (it forced showing of scalar bar and scaling ruler when the user only turned off/on showSliceViewAnnotations)