Improve toolbar layout by spawning new columns rather than using collapased menu

Steps to reproduce:

• use a relatively small screen (mine is a 14", using a 1929×1080 resolution in 16:9)
• open Inkscape
• look at the toolbox menu on the right

What happened?

• the toolbox on the right doesn't directly display all icons

What should have happened?

Rather than hide the additional icons, it would be nice to expand the toolbox with new columns, at least optionally.

Also note that the discoverability of shortcuts is broken on items within hidden part of the toolbox. That is, the directly accessible items provide a message on hover with a description and the keyboard shortuct, which is really excellent. So that's all the more unfortunate that this kind of message won't appear on the extra items, as these is where they would be the most relevant to prevent user from a cumbersome access. I guess this wouldn't happen if the interface would instead add an extra column, rather than appending a collapsible menu.

Inkscape Version and Operating System:

• Inkscape Version: . 1.0 (4035a4fb49, 2020-05-01)
• Operating System: Fedora
• Operating System version: 23

Additional suggestion