feat(parser): Support Swift Package.resolved schema 2+

[kublaios]

The library currently only parses Swift Package Manager lock file schema version 1. In the newer versions (2 and 3), the JSON structure is slightly different:

{
  "object": {
    "pins": [
      {
        "package": "SwiftCheck",
        "repositoryURL": "git@github.com:typelift/SwiftCheck.git",
        "state": ...
      }
    ]
  },
  "version": 1
}

{
  "pins" : [
    {
      "identity" : "colorizer",
      "kind" : "remoteSourceControl",
      "location" : "https://github.com/getGuaka/Colorizer.git",
      "state" : ...
    }
  ],
  "version" : 2
}

This PR extends SPM support by parsing newer schema versions.