Trigger the "Details" action when clicking on an empty file row space

Clicking on an empty space in a file row causes the details view to be
shown. As it is a user initiated action on the file list now it is done
by triggering the Details action instead of directly calling
"_updateDetailsView"; the result is the same in both cases, but using
the action is more consistent (clicking on the file name triggers the
default action, and clicking on the inline actions triggers those
actions) and also makes possible to use the "beforeTriggerAction" and
"afterTriggerAction" listeners.

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>