[forms] Add autocomplete attribute for formrenderers
If you set form.autocomplete = False, the form renderer
in the open form tag will add the html option 'autocomplete=off'.
It allows to disable the functionality of some browsers to fill in
some forms automatically (for instance a profile with login/password)
Closes #3747294
etc/init.d
etc/cubicweb.d
etc/bash_completion.d
usr/bin
usr/share/doc/cubicweb-ctl
var/log/cubicweb
var/lib/cubicweb/backup
var/lib/cubicweb/instances