Top & bottom docked AV panel does not correctly reclaim space when hidden

[Fyorl]

Originally reported by Dick K#6417 https://discord.com/channels/170995199584108546/956306859491471420/1014618979022688336

OS, Hosting, Browser (if applicable): Win10, Self-Hosting, Chrome
Short Description of bug: A/V Docking Positions Top & Bottom Fail to Reposition Other Controls When A/V Window Undocked
Simple steps to reproduce the bug: (V10 Stable) Open scene using Foundry A/V with doc position specified as Top or Bottom. Undock A/V window. Observe that dock background is removed but screen controls, scene buttons, macro bar, are left in position. Bug does not occur with Left & Right dock positions.

[Dick-K]

Thanks!