FormField make default value avaliable in __get function.

[peter1szalatnay]

Is your feature request related to a problem? Please describe.

It would be good to be able to check if the current selected form field value is the default or not.

Example:

$active = $field->value != $field->default ? true : false;

Right now default always return null as it is not in the allowed __get list.

Describe the solution you'd like

Add 'default' to the switch case for FormField::__get function.

Additional context