bug: Fixes parallelization and improves output logic

[mshudrak]

1. Fixes Under certain pip setup gcp_scanner raises can not pickle _cffi_Backend.FFI object #267 when gcp_scanner would hang indefinetely
2. Output file does not contain projects parent node anymore
3. Minor code formating using pyformat

Fixes #271. GCP Scanner does not rely on multiprocessing and future frameworks anymore. We use threads and implement our own logic to handle number workers count.

Added new option to control number of threads.

[mshudrak]

@yahia3200 FYI: I changed the output file format a bit by removing projects {}. The old one did not make sense. Could you please reflect that in the visualization tool (It will likely fail to parse the new one). Thanks!

The new format is like this:

{
  "project_info": {
    "projectNumber": "1076721540910",
    "projectId": "test-gcp-scanner-2",
    "lifecycleState": "ACTIVE",
    "name": "test-gcp-scanner-2",
    "createTime": "2023-04-26T18:09:13.431Z"
  },
  "service_account_chain": [],
  "current_service_account": "mshudrak@google.com",
  "token_scopes": [
    "openid",
    "https://www.googleapis.com/auth/userinfo.email",
    "https://www.googleapis.com/auth/cloud-platform",
    "https://www.googleapis.com/auth/appengine.admin",
    "https://www.googleapis.com/auth/compute",
    "https://www.googleapis.com/auth/accounts.reauth"
  ],
  "service_account_edges": {},
  "dns_policies": [
    {
      "id": "2473340462499062447",
      "name": "test-policy",
      "enableInboundForwarding": true,
      "description": "A test policy",
      "networks": [
        {
          "networkUrl": "https://compute.googleapis.com/compute/v1/projects/test-gcp-scanner-2/global/networks/test-vpc",
          "kind": "dns#policyNetwork"
        }
      ],
      "enableLogging": false,
      "kind": "dns#policy"
    }
  ],
  ...
}

Basically, we are not anymore nesting into projects. Let me know if this is a major change. I can revert it back if needed.

[yahia3200]

@yahia3200 FYI: I changed the output file format a bit by removing projects {}. The old one did not make sense. Could you please reflect that in the visualization tool (It will likely fail to parse the new one). Thanks!

The new format is like this:

{
  "project_info": {
    "projectNumber": "1076721540910",
    "projectId": "test-gcp-scanner-2",
    "lifecycleState": "ACTIVE",
    "name": "test-gcp-scanner-2",
    "createTime": "2023-04-26T18:09:13.431Z"
  },
  "service_account_chain": [],
  "current_service_account": "mshudrak@google.com",
  "token_scopes": [
    "openid",
    "https://www.googleapis.com/auth/userinfo.email",
    "https://www.googleapis.com/auth/cloud-platform",
    "https://www.googleapis.com/auth/appengine.admin",
    "https://www.googleapis.com/auth/compute",
    "https://www.googleapis.com/auth/accounts.reauth"
  ],
  "service_account_edges": {},
  "dns_policies": [
    {
      "id": "2473340462499062447",
      "name": "test-policy",
      "enableInboundForwarding": true,
      "description": "A test policy",
      "networks": [
        {
          "networkUrl": "https://compute.googleapis.com/compute/v1/projects/test-gcp-scanner-2/global/networks/test-vpc",
          "kind": "dns#policyNetwork"
        }
      ],
      "enableLogging": false,
      "kind": "dns#policy"
    }
  ],
  ...
}

Basically, we are not anymore nesting into projects. Let me know if this is a major change. I can revert it back if needed.

fixed with #285