Add a scrollbar to the Add Custom Fields to project dialog

When adding existing custom fields to a project via the Manage Custom Fields dialog, a very short list of recent fields is displayed along with a text box for typing a field name to search. However, if I don’t know the name of the field but would like to simple view all of the available fields I am unable to do that. The dialog already has a scrollbar, why not display all of the fields in the scrollable field to make them easier to find?