Popout HUD on Mac disables Actions and other tabs

When you pop out the HUD window on a Mac it seems to be modal. While the HUD is floating in front of the other windows, its not possible to click actions or select other tabs like messages, or gauges etc.

To reproduce
1. Start Mission Planner
2. Double click on the HUD window
3. Try to click on Actions, Messages or any of the other tabs - nothing happens.

1. Start Mission Planner
2. Click on the actions tab
3. Double click on the HUD window
4. try to click on one of the dropdowns or buttons on the Actions tab - nothing happens.

Build
Mission Planner for Mac
I don't know - the About window says 1.0(1), but I don't think it's right.
I downloaded build 441 on 15 Oct 2021 and see the same behaviour

#### Airframe type
I'm using it for ArduPlane but I don't think that matters.

#### Hardware type
PixRacer R15

#### Logs
_Please provide a link to any relevant logs that show the issue_

Start by reproducing the issue in Mission Planner for Mac: pop out the HUD, then try the Actions, Messages, and other tabs, including the Actions controls. Trace the HUD popout and window interaction behavior. Done means the floating HUD no longer prevents selecting other tabs or using their buttons and dropdowns.

Written by the indexing model from the issue text.