Support dnsinfo and nwi custom objects

[puffyCid]

Describe the issue
While reviewing statedump events, two new custom objects were identified:

• dnsinfo
• nwi

These events show up when the statedump event type is 3 (which is custom object)
Both seem to be part of macOS configd daemon.

dnsinfo seems to be a structure containing dns_config_t information
https://opensource.apple.com/source/configd/configd-596.12/dnsinfo/dnsinfo.h.auto.html

Brief snippet

== StateDump ===========================================================
chunk 393:          tag:0x6003, subtag:0x0000, length:1748
proc_id:            105@248
cur_aid:            80000000000405d0
timestamp:          317922751662556
ttl:                14
sender:             26CB0BA5-A028-3160-8AA9-2925793D202E
State Data:         
    title:          DNS Configuration
    size:           1500
    type:           3 / custom
    decoder library:SystemConfiguration, decoder type dnsinfo

DNS configuration

resolver #1
  search domain[0] : lan
  nameserver[0] : 192.168.1.1
  if_index : 6 (en0)
  flags    : 0x00000002 (Request A records)
  reach    : 0x00020002 (Reachable,Directly Reachable Address)
  config id: Default: 0

resolver #2
  domain   : local
  options  : mdns
  timeout  : 5
  flags    : 0x00000002 (Request A records)
  reach    : 0x00000000 (Not Reachable)
  order    : 300000
  config id: Multicast DNS: 0
....

nwi I have not looked into much but appears to contain info about the network interface
Further info about this structure might found under:
https://opensource.apple.com/source/configd/configd-1109.60.2/nwi/

Brief snippet:

== StateDump ===========================================================
chunk 22390:        tag:0x6003, subtag:0x0000, length:1200
proc_id:            105@248
cur_aid:            80000000000405d0
timestamp:          317922751664855
ttl:                14
sender:             26CB0BA5-A028-3160-8AA9-2925793D202E
State Data:         
    title:          Network information
    size:           952
    type:           3 / custom
    decoder library:SystemConfiguration, decoder type nwi

Network information (generation 32469211037191 size=952)
IPv4 network interface information
     en0 : flags      : 0x5 (IPv4,DNS)
           address    : 192.168.1.231
           reach      : 0x00000002 (Reachable)
           rank       : 0x01000001 (Default, 1)
           signature  : {length = 20, bytes = 0x4fbc10c583230625d1e54cf00f8d51a12b9f20a3}
           generation : 32469211037191
   REACH : flags 0x00000002 (Reachable)
...

Steps to quickly reproduce:

1. Collect logs on system sudo log collect. This should output system_logs.logarchive
2. Examine the contents of system_logs.logarchive and delete all logs in Persist and Signpost directories. This will make parsing even faster
3. Run latest version of unifiedlog_parser example
4. Review output.csv for any results with: Unsupported Statedump object: DNS Configuration-AAAA.... or Unsupported Statedump object: Network information-AQYXIAQAAA...

The log command can be used to further examine the collected logarchive

Expected behavior
macos-unifiedlogs parses the custom objects correctly

Actual behavior
Currently we just base64 encode the data

[puffyCid]

For parsing these objects it will likely require another decoder under src/decoders/
Since these objects are part of the configd daemon, probably best to put them in a separate file like decoders/configs.rs