Add dummy modes for kiosk mode.

This allows us to keep the mode_enter() calls in the code untouched, because
all modes are still available, event if they don't do anything.
Don't register inspector event in kiosk mode.

There is no way, or should be no way to open the webinspector, so there's no
need to set the event listeners to the webinspector events.
Remove if condition for none debug mode.