feat(profile): manage newsletter subscription

src/app/form/footer-form/footer-form.component.ts

src/app/models/subscription.model.ts

...sletter-subscription/newsletter-subscription.component.ts

...file/profile-newsletter/profile-newsletter.component.html

...rofile/profile-newsletter/profile-newsletter.component.ts

src/app/profile/profile.component.html

src/app/profile/profile.module.ts

src/app/services/newsletter.service.ts