Merge branch 'OZG-7773-Nachrichten-auf-ungelesen-setzen' into 'main'

...iguration/src/lib/menu-container/menu/menu.component.html

...ntainer/user-list/user/user-data/user-data.component.html

...ent/libs/bescheid-shared/src/lib/bescheid.service.spec.ts

alfa-client/libs/bescheid-shared/src/lib/bescheid.service.ts

alfa-client/libs/design-system/src/assets/mail-unread.svg

alfa-client/libs/design-system/src/assets/mail.svg

alfa-client/libs/design-system/src/index.ts

alfa-client/libs/design-system/src/lib/icon/icon.stories.ts

...ystem/src/lib/icons/mail-icon/mail-icon.component.spec.ts

...ign-system/src/lib/icons/mail-icon/mail-icon.component.ts

...esign-system/src/lib/icons/mail-icon/mail-icon.stories.ts

...libs/navigation-shared/src/lib/navigation.service.spec.ts

...ient/libs/navigation-shared/src/lib/navigation.service.ts

alfa-client/libs/postfach-shared/src/lib/postfach.linkrel.ts

.../libs/postfach-shared/src/lib/postfach.repository.spec.ts

...lient/libs/postfach-shared/src/lib/postfach.repository.ts

...ent/libs/postfach-shared/src/lib/postfach.service.spec.ts

alfa-client/libs/postfach-shared/src/lib/postfach.service.ts

alfa-client/libs/postfach-shared/test/postfach.ts

.../postfach-mail-button/postfach-mail-button.component.html