Rethink editing enabled/disabled

[developster]

Right now, whenever a form component is enabled or disabled is controlled by firing EditingDisabledEvent or EditingEnabledEvent from the page.

This does not cover the case if the form will have new inputs rendered after the event was fired. For example when only a part of the form is updated, then newly added form components may be out of sync with the rest of the form components that were rendered on page load.

Maybe we can make the form be the controller, and if form is enabled then all form components will honor this setting, and vice versa, when form is disabled component will be disabled as well. This could be a behavior, if attached to a form component will control its enabled flag by looking at the form.

It is a low priority task because we don't have any current issues related to that.