Add hotkeys to cycle through tabs in Preferences window

Suggesting to add the following two sets of hotkeys to be able to cycle through tabs in all XFCE Settings windows.
Ctrl + Tab = Next Tab
Ctrl + PageDown = Next Tab
Ctrl + Shift + Tab = Previous Tab
Ctrl + PageUp = Previous Tab

I do not think there will be any conflicts with these hotkeys, for example "Shortcuts" tab opens up dialog to set shortcuts so do not think will cause any issues.

I made a general post about this in XFCE Settings section that can be found here
xfce/xfce4-settings#602

Not sure if Settings code would also apply to Preferences in this application as well, but just in case it does not.