Allow layouts to be assigned per-workspace

[vaxerski]

Discussion link

https://github.com/hyprwm/Hyprland/discussions/10192

Description

This is quite a big thing to do, so I would advise against doing it unless your name is vaxry.

In general, the key parts are:

• splitting layout inheritance into something like simplelayout and fulllayout where the latter "takes over" everything, while the former can be confined to a workspace.
• fixing some window dnd funsies
• refactoring the available layouts into simple layouts (none of the default ones need floating management)