Sort images timestamp 11986

Couple of small bug-fixes - to test:

 - As web Admin, edit a group (or create a new group). The list of members to add to the group should be sorted by last name. Also the placeholder text for members and owners (when the fields are empty) should indicate that you "Type" to add/filter names. https://trac.openmicroscopy.org.uk/ome/ticket/11985.

 - Browse images in the centre panel, choosing the 'list' view. Should see that the Date column also has time info and images can be sorted by time. https://trac.openmicroscopy.org.uk/ome/ticket/11986