This fixes a long-standing bug where if you tried to click in the
search box for a multiple select while there was text in it, the
dropdown would close and the text would be cleared. This caused
many unexpected issues, because it meant that you could only use
your keyboard to edit text within the search box.
This will still clear out the search field if you click within the
area of the selection which is not the search field. I'm not sure
if that is also unexpected behaviour, so for now I am going to
maintain it.
Fixes#3517Fixes#3808Fixes#5491Closes#5551
f2d527ea97