Add a command to influence keyboard shortcuts inhibitors. In its current
form it can be used to activate, deactivate or toggle an existing
inhibitor on the surface currently receiving input. This can be used to
define an escape shortcut such as:
bindsym --inhibited $mod+Escape seat - shortcuts_inhibitor deactivate
It also allows the user to configure a per-seat default of whether
keyboard inhibitors are honoured by default (the default) or not. Using
the activate/toggle command they can then enable the lingering inhibitor
at a later time of their choosing.
As a side effect this allows to specifically address a named seat for
actions as well, whatever use-case that might serve.
Signed-off-by: Michael Weiser <michael.weiser@gmx.de>