CNID/MySQL: Quote UUID table names

MySQL forbids unquoted table names that begin with a digit. We use UUIDs
as table names, which sometimes begin with a character and sometimes
begin with a digit.  Quote the table names everywhere we use them to
make the MySQL syntax valid.

https://sourceforge.net/p/netatalk/bugs/585/

Signed-off-by: Brian Campbell <brian.campbell@editshare.com>
Reviewed-by: Ralph Boehme <slow@samba.org>