Window border should be included in the geometry entirely

[YaLTeR]

Other clients (GTK, Qt, sctk themed_window, etc.) include the window border in the geometry. This makes sense, too, given that the geometry is the "visible bounds" from the user's perspective, and the border is certainly a visible part of the window.

In sctk-adwaita, only the title bar is included in the geometry, but the 1 px surrounding borders are not. If I clip clients to geometry in niri, this is what I see, notice how the 1 px border around the example is missing:

Among other things (the 1 px border peaking out of places), this screws with rounded corners a little, because in sctk-adwaita's title bar the circle radius is offset by 1 px (due to the 1 px border outside geometry), whereas in all other clients rounded corners are at the exact corners of the window geometry.