dnsmasq: 'ipset' config sections

dnsmasq: 'ipset' config sections

Allow configuring ipsets with dedicated config sections:

    config ipset
        list name 'ss_rules_dst_forward'
        list name 'ss_rules6_dst_forward'
        list domain 't.me'
        list domain 'telegram.org'

instead of current, rather inconvenient syntax:

    config dnsmasq
        ...
        list ipset '/t.me/telegram.org/ss_rules_dst_forward,ss_rules6_dst_forward'

Current syntax will still continue to work though.

With this change, a LuCI GUI for DNS ipsets should be easy to implement.

Signed-off-by: Aleksandr Mezin <mezin.alexander@gmail.com>
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com> [PKG_RELEASE increase]