MacOS - keep floating windows visible on app unfocus

[kyleboyle]

https://doc.qt.io/qt-6/qt.html

Qt::WA_MacAlwaysShowToolWindow

(on macos) Use a widget attribute to keep the floating dock widgets visible when app loses focus.

[kyleboyle]

a comment on the upcoming fix - floating windows will stay visible only if there is one widget per floating window. If multiple widgets are docked into the same floating window, it will exhibit the default behaviour of disappearing. This appears to be a QT bug. If this is a problem, the work around will be to place individual floating windows as you like.