Record-based global query templates

Created by: Florian Spreckelsen

Right now, user templates are based on records of type UserTemplate with Properties Description and Query (see #104 (closed)) while global shortcuts can only be defined in the corresponding json file. They should be similarly record-based instead, s.th. they can be edited and created from the web interface and without having to restart the server.

Also, there should be no options to create or edit query templates if you're not logged in.