After milestone 2 and WT-13947 all rollback reason messages should have been covered by the get_last_error API. This ticket involves deprecating the rollback reason API. In this case, we should be changing all existing rollback_reason related tests to use the get_last_error API. Furthermore a deprecate label should be added to the rollback_reason API().

Definition of Done
Any usage of rollback_reason() is removed from WT and a deprecate label is added inside rollback_reason() API.