Ensure selected/deselected filters stay on top

This looks a little more "sane", and more closely matches what iOS does
with it's filter chips. This has to manually track which filters were
"just-deselected" and move those even higher up the z stack to ensure
they appear above even when sliding right. This is because the order is
determined by the position left-to-right of the _final_ destination of
the chip. In this case we want anything that's either currently
selected, or was selected and is still fading out to appear on top.

Signed-off-by: Joe Groocock <me@frebib.net>

changelog.d/2809.bugfix

@@ -0,0 +1 @@
+Render selected/deselected room list filters on top