[Netfilter] add mailcow isolation rule to MAILCOW chain

[Netfilter] add mailcow rule to docker-user chain

[Netfilter] add mailcow isolation rule to MAILCOW chain

[Netfilter] add mailcow isolation rule to MAILCOW chain

[Netfilter] set mailcow isolation rule before redis

[Netfilter] clear bans in redis after connecting

[Netfilter] simplify mailcow isolation rule for compatibility with iptables-nft

[Netfilter] stop container after mariadb, redis, dovecot, solr

[Netfilter] simplify mailcow isolation rule for compatibility with iptables-nft

[Netfilter] add exception for mailcow isolation rule for HA setups

[Netfilter] add exception for mailcow isolation rule for HA setups

[Netfilter] add DISABLE_NETFILTER_ISOLATION_RULE

[Netfilter] fix wrong var name

[Netfilter] add DISABLE_NETFILTER_ISOLATION_RULE to update and generate_config sh