Panel: panelclose event does not work

panelclose is not bound to document after _openPanel

Fixes gh-7058

Panel: panelclose event does not work

altered to use _on and _off

Fixes gh-7058

Panel: panelclose event does not work

altered _on and added another test

Fixes gh-7058

Panel: panelclose event does not work

fix use of _on

Fixes gh-7058

Panel: panelclose event does not work

Fixes gh-7058