Multi-column display of popup suggestions

[tkna91]

Currently, only nine popup suggestions (a-l or 1-9) can be displayed, which is inconvenient because it is impossible to list a large number of suggestions when there are many to display.
I think it would be useful to be able to display multiple columns of popup suggestions, as shown in the image below.

Screenshot:

It would then be nice to be able to assign key bindings to advance to the next/previous column of the candidate, or to specify the focus of a column by entering a numerical value.

[eagleoflqj]

Duplicate #902