Please implement the 'Grab all keyboard events' option to allow certain keyboard events to not be consumed

[yurivict]

Is your feature request related to a problem? Please describe.

Please allow the user to toggle the connection option 'Grab all keyboard events' when the screen is in a fullscreen mode.
This way the user would be able to "glance" into the connection with Alt-Tab and go away with another Alt-Tab, and not get stuck in that screen.

Remmina does this right: It allows the user to toggle the 'Grab all keyboard events' option with the button and the keyboard shortcut.

Describe the solution you'd like
At least the Alt-Tab even would not be consumed, and possibly some other events related to navigation.

Describe alternatives you've considered
n/a

Additional context
This feature is very useful when the user shares time between different systems and needs to be able to easily go back and forth.

How it should work

• The session in the browser should have the boolean 'Grab all keyboard events' attribute.
• When it is True - it should work as now.
• When it is False - it should allow Alt-Tab to switch away from the browser to other host windows.
• There should be a configurable keyboard shortcut that toggles 'Grab all keyboard events'.
• There should also be a button in the floating menu to toggle 'Grab all keyboard events'.
• Also, when the floating menu is opened - 'Grab all keyboard events' should be automatically assumed to be False so that the user would be able to move the mouse up, the menu would float out, and the user would be able to Alt-Tab to another host window.