Hi Charpentier Lucas regarding the efficiency of space and accessibility, would it be possible for us to do the resizing it the same way Salesforce do in their Design System? https://salesforce-ux.github.io/dnd-a11y-patterns/#/resize?_k=itupzs

It is almost the same idea that you've implemented here. The difference is that in their case, the same handler is used for mouse interaction and keyboard interaction, just a vertical bar that changes color when focused. The cursor of our handler could also be changed to cursor: col-resize; to keep up with semantics;

Another nice aspect of their interaction is that the handler, usually hidden, is shown when the mouse is over the column, providing a clear indication that resizing is available.

What do you think?

I am on the fence regarding the move icon/handler being placed at the end of the line. I'm more used to it being in the beginning, but I think it is a matter of personal opinion.