chore(button): déplacement du model dans shared

...-components/src/lib/components/button/button.component.ts

...fr-components/src/lib/components/button/button.stories.ts

...ts/ngx-dsfr-components/src/lib/components/button/index.ts

...components/src/lib/components/modal/modal-action.model.ts

...mponents/src/lib/forms/form-input/form-input.component.ts

...ngx-dsfr-components/src/lib/shared/models/button.model.ts

projects/ngx-dsfr-components/src/lib/shared/models/index.ts