Draft: firewallmngr: handling for firewallmngr
Default config for firewall manager, this config is in sync with the default firewall uci config of iowrt. Added library function that read teh uci file of firewallmngr. convert it to generate firewall uci file. added bbf code for Device.Firewall. as microservice handling for Device.NAT object concept to add porttrigger in firewallmngr firewall include section handling