Broken compatibility with Burn My Windows on Wayland if fractional scaling is off

[FelixFourcolor]

(continuation of #528)

Another consequence of commit e242657 (PR #522) is that when fractional scaling is off, Burn My Windows applies its affect at the wrong area.

Without e242657 (pre-v55), the effect is applied exactly on top of the window: screencast

With e242657 (v55), the effect overflows the window boundary: screencast. The overflow part looks like the overflow blur box as described in #528, I assume it's not a coincidence.

I only show in the screencasts one of Burn My Windows' many effects, but in my testing I find most - if not all of them - are similarly broken.

After testing I find the same situation as in #528:

	With e242657	Without e242657
Fractional scaling on	working	broken (#362)
Fractional scaling off	broken (this issue)	working

[aunetx]

Working on this :)

[aunetx]

Uh, actually not really, working on #528 but I guess once it's solved this bug will be too, as Burn my Windows simply takes the blur effect into account in its frame rectangle calculation

[aunetx]

This should be fixed by #534, waiting for some testing :)