Always list a "Current revision" for each available content translation

Simple test scenario:

• Create article in English.
• Translate to German and save as a new revision.
• Look at the revisions tab when you are on the English site. You will see only one translation and you do *not* see the current default revision.

I actually was trying this patch here https://www.drupal.org/project/drupal/issues/2769741 → but didn't work. Then that issue referred to already fixed core issue at https://www.drupal.org/project/drupal/issues/2938947 →

I checked that the particular code has not been added to Diff module.