Make entity_access_field usefull for base fields

Problem/Motivation

For now, if we wanna use the 'entity_access_field' type for the base fields in entity types it is not possible because of some methods that do not exist in that kind of field definition. Also, widgets with multiple values do not support default values and we cannot use the "allowed_values_function".

Proposed resolution

- Check if field definition has method "id", ni another case use "getName" to generate permission.
- Check allowed values by using allowed_values_function if it exists as it done in the options.module
- Update default value in the social_group_field_widget_form_alter to make it possible use multiple values.