Added many hooks. Finished up notifications

...events_registration/recurring_events_registration.api.php

..._events_registration/recurring_events_registration.module

...nts_registration/recurring_events_registration.tokens.inc

...ents_registration/src/Controller/RegistrantController.php

...s/recurring_events_registration/src/Entity/Registrant.php

...ing_events_registration/src/Form/RegistrantDeleteForm.php

...recurring_events_registration/src/Form/RegistrantForm.php

...g_events_registration/src/Form/RegistrantSettingsForm.php

...vents_registration/src/RegistrantAccessControlHandler.php

...g_events_registration/src/RegistrationCreationService.php

recurring_events.api.php

src/EventCreationService.php

src/Form/EventInstanceDeleteForm.php

src/Form/EventSeriesDeleteForm.php

src/Form/EventSeriesForm.php