Fix js validation for subjects, sessions and modalities.

hyrax/app/assets/javascripts/dataset_form.js

...llers/hyrax/crc_datasets/complex_modalities_controller.rb

...rollers/hyrax/crc_datasets/complex_sessions_controller.rb

...rollers/hyrax/crc_datasets/complex_subjects_controller.rb

...iews/hyrax/crc_datasets/complex_modalities/_form.html.erb

.../views/hyrax/crc_datasets/complex_sessions/_form.html.erb

.../views/hyrax/crc_datasets/complex_subjects/_form.html.erb