Radio table view: better experience of table sorting for screen reader users

[TomaszGasior]

Radio list contents can be sorted by clicking table header. It's also possible to focus column header from the keyboard and press "enter".

There is no indicator for screen reader that pressing "enter" button will cause table contents reordering. Also, there is no indicator for screen reader that data is already sorted. The button can be pressed to sort the whole list by that column, and pressed again to sort in reversed order.

It's needed to find best practices about table sorting for accessibility and implement it.

See also #109

#15

[TomaszGasior]

Merged with #109