OZG-7590 adjust e2e tests

...min-e2e/src/components/postfach/postfach.e2e.component.ts

...aendige-stelle/zustaendige-stelle-dialog.e2e.component.ts

.../src/e2e/main-tests/benutzer_rollen/benutzer_rollen.cy.ts

...apps/admin-e2e/src/e2e/main-tests/navigation/ariane.cy.ts

.../apps/admin-e2e/src/e2e/main-tests/navigation/daria.cy.ts

...apps/admin-e2e/src/e2e/main-tests/navigation/safira.cy.ts

...sationseinheiten/organisationseinheiten-hinzufuegen.cy.ts

...organisationseinheiten/organisationseinheiten-laden.cy.ts

...n-e2e/src/e2e/main-tests/postfach/postfach-signatur.cy.ts

...ent/apps/admin-e2e/src/helper/postfach/postfach.helper.ts

.../apps/admin-e2e/src/helper/postfach/postfach.navigator.ts

alfa-client/apps/admin-e2e/src/page-objects/main.po.ts

alfa-client/apps/admin-e2e/src/support/cypress.util.ts

.../lib/postfach-container/postfach-container.component.html