message: Add tests for stratifying to lifted types/terms
diff: >> Yes:
  >> Target := stratified.type_type.
  +>> from_term_to_kind (core.record_type []) Target ?
  +>> Yes:
  +>> Target := stratified.lift (stratified.record_type []).
  +
  +>> from_term_to_kind (core.record_intro []) Target ?
  +>> Impossible.
  +
  >> from_term_to_type (core.record_type []) Target ?
  >> Yes:
  >> Target := stratified.record_type [].
  +>> from_term_to_type (core.record_intro []) Target ?
  +>> Yes:
  +>> Target := stratified.lift (stratified.record_intro []).
  +
  >> from_term_to_term (core.record_intro []) Target ?
  >> Yes:
  >> Target := stratified.record_intro [].
  