MDL-40405 libraries: Deprecate get_child_contexts()
MDL-40405 libraries: Deprecate get_child_contexts()
MDL-40406 libraries: Deprecate create_contexts()
MDL-40406 libraries: Deprecate cleanup_contexts()
MDL-40406 libraries: Deprecate build_context_path()
MDL-40406 libraries: Deprecate rebuild_contexts()
MDL-40407 Libraries: deprecated preload_course_contexts