firewall: fix several ipset integration issues (#15016)

	- Do not consider bitmap storage for IPv6 family sets
	- Move ipset family parameter before any additional option
	- Only emit family parameter for hash sets
	- Do not allow IPv6 iprange for IPv4 sets and vice versa

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@39647 3c298f89-4303-0410-b956-a3cf2f4a3e73