Add a dispatcher for manually triggering swallowing

[vaxerski]

Discussion link

https://github.com/hyprwm/Hyprland/discussions/9882

Description

Add a dispatcher that looks for a parent of the window, and swallows it, on demand. (as opposed to always via the swallow feature)

[alba4k]

rather than being a new dispatcher, can't this be a breaking change to the existing toggleswallow (maybe making it require an extra arg, something like toggleswallow 1)

[grappas]

Or just simply make it work on both enable_swallow = true and false <- on false it just wouldn't swallow automatically.

[ghost]

this would be better off as a new flag to toggleswallow