[sql gen] Properly create UNIQUE index on non string column. Closes #13728492 Unique was previously detected in a loop triggered only for String columns.

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