(bug 44674) Entity search: Prevent closing suggestion list

The change set prevents the suggestion list of the entity selector replacing the native
search box from closing if there are no actual suggestions. If there are no suggestions,
the link to the full-text search will remain visible.

- patch set 4: rebase
- patch set 5: minor fix regarding event handling

Change-Id: I0069a6b1ae1f6264c2a59c29bafffbb6b520a946
Merge "(bug 44674) Entity search: Prevent closing suggestion list"