Final deprecation of the following methods:
- course_modinfo::build_section_cache()
- cm_info::get_deprecated_group_members_only()
- cm_info::is_user_access_restricted_by_group()

Plus throw coding exception for direct calls of the following:
- cm_info::get_url()
- cm_info::get_content()
- cm_info::get_extra_classes()
- cm_info::get_on_click()
- cm_info::get_custom_data()
- cm_info::get_after_link()
- cm_info::get_after_edit_icons()
- cm_info::obtain_dynamic_data()