[Feature] Change order of columns

[sasule]

It would be useful for some users to have the ability to change not only visibility of columns but also the order of columns.
Recently I have to have some config outside of datagrid which tells what columns are shown and in which order.

[radimvaculik]

Thanks for the suggestion, @sasule — this sounds like a useful feature.
Would you be interested in opening a pull request for it? We’d be happy to review and help refine the implementation if needed.