Add Hosts as new Finding Category

[J12934]

🚀 New Host Type Findings

Previously only Open Ports would be used to create Findings. This works great but is lacking if you want to use Nmap for Network Discovery where you don't care about ports but only if the hosts are up or not.

To accommodate this use case we added a new finding type of the category Host. These contain the following information:

{
  "id": "49bf7fd3-8512-4d73-a28f-608e493cd726",
  "category": "Host",
  "name": "Host: localhost",
  "description": "Found a host",
  "location": "localhost",
  "osi_layer": "NETWORK",
  "severity": "INFORMATIONAL",
  "attributes": {
    "hostname": "localhost",
    "ip_address": "127.0.0.1",
    "operating_system": null
  }
}

🚧 Technical Changes

To allow these change, mayor restructuring was required, most notably the extraction of the node-nmap package into this repository to make the required changes to the result parsing.
This also allowed to move the nmap script result parsing into this code, which means that we don't have to parse the xml twice anymore.