Option to autoplace on button hold

[finite tide]

I think an option to autoplace stuff on the hold of a button would be quite nice.

This would affect Building upgrades (Holding middle click) and Nukes (holding main click)

Would be understandable and still nice for me if it was only enabled for solo mode.

[prisma scaffold]

there's a need for more shortcuts customization anyway, if there's a shortcut, it should be customable (look at you, mouse middle click)