FEAT #8489 link front with back to email send test

...istration/sendmail/sendmail-administration.component.html

...istration/sendmail/sendmail-administration.component.scss

...inistration/sendmail/sendmail-administration.component.ts

src/frontend/app/list/basket-list.component.ts

src/frontend/lang/lang-en.ts

src/frontend/lang/lang-fr.ts

src/frontend/lang/lang-nl.ts