Add a Hook To Hide Inactive Widgets

[BFTrick]

Hello,

This is my first feature request so hopefully I'm going through the process correctly. Onto the request...

Adding a hook to remove or hide the Inactive Widgets sidebar on the WordPress Admin Widgets page would be very useful for developers who don't use the area and want to be able to hide it for better UX.

If this is approved I would love to submit a patch. :)

What's wrong with

#inactive-sidebar {
    display: none;
}

?

I figure that writing this programmatically would be better in case CSS id's & classes or HTML structure would ever change for any reason.

Writing this programmatically might be better for future proofing against plugins or themes that could also manipulate the widget area and all sorts of crazy code that adds extra divs, classes, ids, etc.

Thoughts?