Add prop autoClose to GlCollapsibleListbox component

Currently, the GlDisclosureDropdown component supports an autoClose prop which we can set to false if we do not want the dropdown to close when selecting an item. However, GlCollapsibleListbox component does not support this prop.

Certain listbox dropdowns need to remain open once an element is selected because they contain a call to action inside the dropdown itself. One example is the move issue dropdown.