evaluate: reject: check in bridge and inet the network context in reject

evaluate: reject: check in bridge and inet the network context in reject

In Inet tables, we have to check the network context in rules that we use
icmp or icmpv6 reason in reject. To be sure that the context is the correct.
However, for icmpx and tcp reject, we don't need to check it.

In Bridge tables, ee have vlan and arp traffic and they are not supported.
For this things, we have to check the network context. For example:

  nft add rule bridge test-bridge input \
			ether type arp reject with icmp type host-unreachable
or
  nft add rule bridge test-bridge input \
  			ether type vlan reject with tcp reset

In that cases, we have to throw an error. Moreover, we have to accept rules
that the network context is Ipv4 and Ipv6. For example:

  nft add rule -nnn bridge test-bridge input \
			ip protocol tcp reject with tcp reset

Moreover, this patch refactor the code for check the family for bridge and inet
tables.

Signed-off-by: Alvaro Neira Ayuso <alvaroneay@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>