Internal issue 3147 - IcDataTable default column's sort order

Currently, we are able to define the sort options of the table (e.g.  ["descending", "ascending", "unsorted"]) and specify a default sort column (which uses the first available sort option) but we cannot specify a default sort direction without amending the sort orders. This is really inconvenient, since we may want one column to be sorted by default in a different direction without it affecting the default sort options of the table.

*Acceptance Criteria:*
* I create a table with sorting orders
* I give it a default sort column

* I give it a default sort direction
* The table correctly maintains the sort options (and order) and sorts the column by the specified direction.

Start by locating the IcDataTable sorting implementation and its existing tests. Verify how sorting orders and the default sort column are currently configured, then define completion by confirming that a separate default sort direction is accepted while preserving the configured sort options and their order.

Written by the indexing model from the issue text.