Item tracking fixes (#12146)

* Cleanup; Fix lang keys

* Documentation

* Typos

* Distinct the results

* Changed GetPagedRelationsForItems to GetPagedRelationsForItem as we would only expect a single id to be passed when calling this + fix more docs

* Changed to the correct reference

* Unused code

* Only load references when info tab is clicked

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

src/Umbraco.Infrastructure/Persistence/NPocoSqlExtensions.cs

@@ -659,6 +659,12 @@ namespace Umbraco.Extensions
             return sql;
         }
 
+        public static Sql<ISqlContext> SelectDistinct(this Sql<ISqlContext> sql, params object[] columns)
+        {
+            sql.Append("SELECT DISTINCT " + string.Join(", ", columns));
+            return sql;
+        }
+
         //this.Append("SELECT " + string.Join(", ", columns), new object[0]);
 
         /// <summary>