Access denied to published private file if original translation is unpublished

Problem/Motivation

When trying to access a file that is referenced by a single entity, access is denied if that entity's original translation is unpublished, even if a published translation referencing the same file exists.

Steps to reproduce:

1. Use a multilingual site with content_translation
2. Create a translatable entity with a file/image field as unpublished
3. Create a published translation of the entity
4. Access the file as guest

Expected result:
File is displayed, because the translation is accessible.

Actual result:
The user receives a 403.

Proposed resolution

Check all translations of the referencing entity and grant file access if at least one translation is accessible. (Field access should still be checked.)

Remaining tasks

Write tests to reproduce the issue.