feat(date): short iso string

CHANGELOG.md

...x-dsfr-components/src/lib/patterns/date/date.component.ts

projects/ngx-dsfr-components/src/lib/patterns/date/date.mdx

...-dsfr-components/src/lib/patterns/date/date.model.spec.ts

...s/ngx-dsfr-components/src/lib/patterns/date/date.model.ts

...nts/src/lib/patterns/date/demo/demo-date-iso.component.ts

...x-dsfr-components/src/lib/shared/utils/date-utils.spec.ts

...ts/ngx-dsfr-components/src/lib/shared/utils/date-utils.ts