Display current revision for translations on first page only

In hindsight, happy to move this to 3227907 as I don't think we need two issues for this.

Adding patch version if it helps.

Adding new version of the patch which also takes in to account the issue described here (another core issue): https://www.drupal.org/project/drupal/issues/3092558 🐛 Revisions log on translated nodes should not show original language revisions, should show revisions of translated content RTBC

This only affects new translations that only have draft revisions and no published version - core Drupal will display the default language revision page which is confusing for the user.

I've moved the changes from the latest patch across to this patch and also added a fallback which checks if the there is no current revision (as per the new method) and the node is unpublished; in this case we need to assume the first revision is the latest because they should all be drafts and there will be no revision_default.

Another slight tweak - this time to fix an issue with the current revision link going to the wrong place in certain scenarios. If there are no published revisions we want to point it at the revision (as the 'view' tab will display the published version, and this is a draft revision), otherwise we want it to link to the same as the 'view' tab.

re-roll patch #10.

Please update to use an MR