* implementation of i18n for schemas

docs/docs/provider_schema.md

src/consents/serializers.py

src/consents/views.py

src/frontend/package-lock.json

src/frontend/package.json

src/frontend/src/app/app.component.scss

...frontend/src/app/consent-management/consentDeclaration.ts

...agement/provider-settings/provider-setting.component.html

...anagement/provider-settings/provider-setting.component.ts

...d/src/app/consent-management/wizard/wizard.component.html

...d/src/app/consent-management/wizard/wizard.component.scss

...end/src/app/consent-management/wizard/wizard.component.ts

src/frontend/src/app/navigation/footer/footer.component.html

src/frontend/src/app/navigation/header/header.component.html

src/frontend/src/app/navigation/header/header.component.scss

src/frontend/src/app/navigation/header/header.component.ts

src/frontend/src/app/services/api.service.ts

src/frontend/src/app/services/language.service.ts

src/frontend/src/environments/environment.ts

src/frontend/src/locale/messages.de.xlf