Dock and Panel on bottom + Dock autohide: panel buttons not clickable

[theduke]

To reproduce:

• Set panel position to bottom
• Set dock position to bottom
• Set dock to autohide

Result: Buttons in the panel (eg the various widgets in the right) are not clickable, and are also not highlighted on mouseover.

[WatchMkr]

We are tracking this issue here: https://github.com/pop-os/cosmic-panel/issues/67