Test Vokab::Item::*->display_all

- changed Vokab::Item::Word::Verb to use 7 entry attributes rather than
  one hash attribute
Reverted changes to Vokab::Item::Word::Verb

- conjugation field is now a hashref again
- minor changes to some attributes' types (alternate isa Str,
  display_gender isa Bool)

- consolidated all Vokab::Item::* test data into a single array
Tested Vokab::Item::*->set_all

- Data on attrs is now a hashref, not a list. Necessary for setting
  ancestor fields in test_set_all