Resolve #3071666 "No form validation"
Closes #3071666
- Reroll and clean up previous patch.
- Add validation for start/end dates/times that tests in the previous patch expected to exist but didn't for some reason.
- Replace usage of non-existent
Drupal\date_recur_entity_test\Entity\DrEntityTestBasic
. - Fix DrupalDateTime values in
Drupal\date_recur_modular\Plugin\Field\FieldWidget\DateRecurModularAlphaWidget::validateModularWidget
unexpectedly being null and causing tests to fail.