Move default columns to a backend_layout configuration
Following the thread
We came up with a concept of migrating the default 1,0,2,3 column to a backend_layout configuration
This makes it easier to work with the db_layout.php class, as there will be only one way to render the columns.
This task is a part of implementing drag'n'drop functionality, as this will clean up some code output and only have 1(!) markup