this adds an option to set the helplink on the global event
also we now only set the link instead of the complete handler,
which is now static and gets the url from a property
(which we will set directly for other help buttons)
Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
Next / OK are already displayed in blue, which is the 'call-to-action'
color we use everywhere.
To prevent stealing attention from these buttons, switch help button
to grey
This help button is meant to be added on InputPanels, where a
link to an online documentation chapter or subschapter is available.
Clicking on the help button will open the help in a new
browser tab.
Original idea similar to the pfSense GUI.
