Added support for non-strict unordered assertion mode.

Added a new mode "NON_STRICT_UNORDERED" to DatabaseAssertionMode enum to be able to compare actual and expected data ignoring order of rows. Corresponding class to this mode sorts two data sets using SortedTable.

When using only NON_STRICT mode, our test cases pass sometimes but fails sometimes because the order of actual data can not match expected data every time so we need to this behaviour.