V14: Unpublish multiple cultures (#15789)

* Refactor to accept multiple cultures

* Add test

* Move logic into service

* Remember to complete scope

* Move scope creation.

* Add test

* Close scope on early return

* Handle invalid cultures with bad request

* Handle valid cultures based on content

* Change return type if a culture is required

* Refactor content publishing service to have 1 unpublish method

* Update tests

* Return better error

* Scope completes

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Co-authored-by: Bjarke Berg <mail@bergmania.dk>

src/Umbraco.Core/Models/ContentRepositoryExtensions.cs

@@ -380,7 +380,7 @@ public static class ContentRepositoryExtensions
 
         var keepProcessing = true;
 
-        if (culture == "*")
+        if (culture == "*" || (content.ContentType.VariesByCulture() is false && culture is null))
         {
             // all cultures
             content.ClearPublishInfos();