As an editor I want to see the Label of an EntitySchema in a fallback language if it is not available in my interface language in order to have a chance of understanding what the Entity Schema is about.

Problem:
We currently have no support for language fallback for Entity Schemas. We should have it for the label at the top of the page and in the page title.

Example:
https://www.wikidata.org/wiki/EntitySchema:E2?uselang=zh has no label in zh at the time of this writing but does have a label in en. That should be shown.

Screenshot:

BDD
GIVEN an Entity Schema page
AND no label in interface language
AND label in a fallback language from the interface language
WHEN viewing the Entity Schema page
THEN the schema's label is shown in the fallback language in the header of the Entity Schema and in the HTML title of the page

Acceptance criteria:

• Language fallback are applied on Entity Schema pages.
• Language fallbacks on Entity Schema pages follow the same fallback chain as on Item and Property pages.
• A label from a fallback language is indicated in the same visual way as on Item and Property pages.