Lock screen icon in taskbar if admin password entered at startup

If a user selects an administrator password on startup it would be very useful to have a lock icon shortcut.

When clicked the screen turns blank until the keyboard or mouse is clicked. Then it asks for the admin password which was selected at startup to unlock the screen.

Reason this is needed is often times a Tails user might step away from the laptop for 2 - 3 minutes to use the restroom but doesn’t want to leave the computer open unlocked and doesn’t want to save everything and shutdown for a 2 - 3 minute bathroom break.

If user selected admin password at startup cannot be used for the lock screen password perhaps on startup if a user selects a checkbox “Screen Lock” a password field is visible where they can set their screen lock password on startup.

Related issues

• Is duplicate of #5684 (closed)

Original created by @darkgrid on 7045 (Redmine)