FIX #16305 TIME 0:45 Contact creation: alert on duplicate first name / last name

...ge/contactSearchModal/contact-search-modal.component.html

...ge/contactSearchModal/contact-search-modal.component.scss

...page/contactSearchModal/contact-search-modal.component.ts

...nistration/contact/page/form/contacts-form.component.html

...nistration/contact/page/form/contacts-form.component.scss

...ministration/contact/page/form/contacts-form.component.ts

src/frontend/app/app.module.ts

src/lang/lang-en.json

src/lang/lang-fr.json