TreeTable: please add props expandedIcon and collapsedIcon

[Sergei-Shvets]

Hello!

I have one request. Please can you add two props to the TreeTable component – expandedIcon and collapsedIcon for changing arrows.

I need to change these icons. But I can’t)

Other components like Tree and DataTable have such props and it’s really easy to change icons.

I hope it’s not difficult for you)

Thanks a lot!