Make it easier to delete multiple plugins from panel

Submitted by sco..@..il.com

Assigned to Xfce Bug Triage

Link to original bug (#15402)

Description

When i edit the list of items/plugin in the panel and select an item and delete it the list scrolls up to the top each time i have deleted an item.

This is annoying when i have to delete a lot of items because i have to scroll down each time.

So maybe would be nice to be able to select multiple items with like Ctrl+click and then only have to press delete and confirm once. Or maybe have check boxes to the side of each item so the user can select what to delete before pressing the delete button.

Version: 4.13.4