Move handling of clearOnHide property from evaluate_form_logic to PropertyAction

[viktorvanwijk]

Part of #5117, see comment.

This will enable tracking of variable changes during instead of after logic evaluation.

[viktorvanwijk]

This is not straightforward, unfortunately. Problems:

• It reintroduces a old bugs (Hidden fields with default value present in data #1755, Data of previously filled fields that become hidden is still present in the summary #1527, and Hiding fieldsets doesn't clear their data #2340)
• Fields that are hidden by default and shown through a PropertyAction of a logic rule will not get cleared when hidden again. This is because the logic rule is not triggered when the field gets hidden again, as the default state of the field is 'hidden', so the clearOnHide property is not checked. (This might actually be the root cause as well for (some of) the bugs listed above)

Perhaps something to look into: for components with the clearOnHide property set, we create a special logic rule with a corresponding action that will always be evaluated. This means we can move handling of the property to PropertyAction.eval. Not sure yet about implementation details, though.