U4-8754 Single content queries like Get(int id) for content, media and members needs to execute a TOP 1 (or LIMIT 1)

updated a bunch of the remaining repositories to also use this pattern where applicable (repos using mappers aren't compatible without more work).

src/Umbraco.Core/Persistence/SqlSyntax/MySqlSyntaxProvider.cs

@@ -178,6 +178,11 @@ ORDER BY TABLE_NAME, INDEX_NAME",
             return result > 0;
         }
 
+        public override Sql SelectTop(Sql sql, int top)
+        {
+            return new Sql(string.Concat(sql.SQL, " LIMIT ", top), sql.Arguments);
+        }
+
         public override bool SupportsClustered()
         {
             return true;