There is a way to manage tables in rules, but there is no way to
manage tables for chains when setting policy.

Looks like pillar structure is bad from the beginning and to
not break backward compatibility, as same chain names may occur in
different tables, so it is proposed to check if 'chain.policy' is
map. And if it is, specific policies would be ensured for specific
tables, otherwise table 'filter' would be used as a fallback.

To ensure chains in specific tables we iterate over all rules in
each chain.

This hash is valid:

parameters:
  iptables:
    service:
      enabled: true
      chain:
        OUTPUT:
          policy: ACCEPT
        FORWARD:
          policy:
          - table: mangle
            policy: DROP
        INPUT:
          policy:
          - table: nat
            policy: ACCEPT
          rules:
          - jump: ACCEPT
            protocol: icmp
        POSTROUTING:
          rules:
          - jump: MASQUERADE
            protocol: icmp
            out_interface: ens3
            table: nat

Prod-Related: CEEMCP-12
Prod-Related: EME-313

Change-Id: Ib5ba97dad165d3ef2dec7e053b391ea36a996103