[Feature request] add option to toggle hide

[bonecountysheriff]

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

I'd like to use a key shortcut to toggle the visibility of the panel,
like in i3 or qtile.

Describe the solution you'd like

Add an option (like -t --toggle) so that running lxqt-panel -t should hide
any running panel if visible and vice versa. Maybe only make this work if auto-hide
is disabled.

Describe eventual alternatives you've considered

I currently use xdotool to toggle the visibility, but this solution is sort of
a hack and doesn't use lxqt's hide animation.

Context

I don't like panels taking up space meant for windows and so I try to hide them
using whatever way is possible. Problem is that the panel tends to show up
whenever I inadvertently hit the edge. Using a hotkey combination instead
is much better.