Floating windows flicker when opened over maximized windows

[ryanabx]

My hunch is this commit caused it, as it caused a few other regressions with floating windows: https://github.com/pop-os/cosmic-comp/commit/a3df48fe176e3fdabcc3eb8d54e21fc9aa2fe3d5

To reproduce:

Maximize window A Drag window B to tile to the left Drag window C to tile to the right

Result:

Only B or C can be shown at a time, never both

This oddly does not occur UNLESS there is a maximized window behind windows B and C

Screenshots (since screen capture is broken in a recent update)

[git-f0x]

From my testing, tiling the windows isn't necessary. Only one window can be visible over a maximized window in all cases (2 windows can be visible while dragging one of them, but that's probably related to an already reported issue).

[ryanabx]

From my testing, tiling the windows isn't necessary.

It's just an easy way to reproduce

[jacobgkau]

This is still happening on 9cd553e.

It seems to have gotten worse with recent updates; I just applied updates & rebooted, and now, even a single floating window over a maximized window flickers.

[Drakulix]

Fixed by da9af7ad23ea91d850ab81c47deefecd40c1f972