network: DHCP server Add support to transmit SIP server
1. DHCP server trasmit
2. Client parses and saves in leases
Implements http://www.rfc-editor.org/rfc/rfc3361.txt
```
Frame 134: 348 bytes on wire (2784 bits), 348 bytes captured (2784 bits) on interface 0
Ethernet II, Src: 42:65:85:d6:4e:32 (42:65:85:d6:4e:32), Dst: 1e:04:f8:b8:2f:d4 (1e:04:f8:b8:2f:d4)
Internet Protocol Version 4, Src: 192.168.5.1, Dst: 192.168.5.11
User Datagram Protocol, Src Port: 67, Dst Port: 68
Dynamic Host Configuration Protocol (ACK)
Message type: Boot Reply (2)
Hardware type: Ethernet (0x01)
Hardware address length: 6
Hops: 0
Transaction ID: 0x7cc87cb4
Seconds elapsed: 0
Bootp flags: 0x0000 (Unicast)
Client IP address: 0.0.0.0
Your (client) IP address: 192.168.5.11
Next server IP address: 0.0.0.0
Relay agent IP address: 0.0.0.0
Client MAC address: 1e:04:f8:b8:2f:d4 (1e:04:f8:b8:2f:d4)
Client hardware address padding:
00000000000000000000
Server host name not given
Boot file name not given
Magic cookie: DHCP
Option: (53) DHCP Message Type (ACK)
Length: 1
DHCP: ACK (5)
Option: (51) IP Address Lease Time
Length: 4
IP Address Lease Time: (3600s) 1 hour
Option: (1) Subnet Mask (255.255.255.0)
Length: 4
Subnet Mask: 255.255.255.0
Option: (3) Router
Length: 4
Router: 192.168.5.1
Option: (6) Domain Name Server
Length: 4
Domain Name Server: 192.168.5.1
Option: (42) Network Time Protocol Servers
Length: 4
Network Time Protocol Server: 192.168.1.1
Option: (120) SIP Servers <=====here
Length: 9
SIP Server Encoding: IPv4 Address (1)
SIP Server Address: 192.168.1.1
SIP Server Address: 192.168.5.2
Option: (101) TCode
Length: 13
TZ TCode: Europe/Berlin
Option: (54) DHCP Server Identifier (192.168.5.1)
Length: 4
DHCP Server Identifier: 192.168.5.1
Option: (255) End
Option End: 255
```
```
cat /run/systemd/netif/state ✔ ⚡ 3148 16:40:51
OPER_STATE=routable
CARRIER_STATE=carrier
ADDRESS_STATE=routable
DNS=192.168.94.2 192.168.5.1
NTP=192.168.5.1
SIP=192.168.1.1 192.168.5.2
```
aa