(fwGui): manage inverse actions

What does this MR do?

Handle the inverse actions behaviour.

When the inverse is set, it means that the behaviour of toolbar button (or menu item) is inverted. It is like if it's internal state return false when it is checked and true when unchecked.

How to test it?

• Build and launch TutoGui
• Play with the view5 visibility (inverted) button
• See that when the button is connected with a SBooleanSlotCaller to a setVisibility slot in the .xml
• But thanks to the inverse=true attribute in the state configuration tag, the view is hide when checked and show when unchecked, witch is the inverse of the usual behaviour.

Some results

Additional tests to run

• Build on Windows
• Build on Linux