Add a WP_List_Table data source

[zackkatz]

It would be awesome if DataKit could get ahead of the curve and provide an easy migration path for people using WP_List_Table.

I see this working by passing a WP_List_Table object into the decorator, which would figure out the settings and apply them.

[sc0ttkclark]

I'd love to see this and maybe even help build this part